Mind, Body, and Brain 1

The biology of behaviour

All 'nervous tissue' is found in the body.  Two types of cells in the nervous system: Neurons and Glial cells   Two subsystems:  Central Nervous System (CNS) - Brain and Spinal cord 2. Peripheral Nervous System (PNS) - Everything other than the brain and spinal cord - Sensory connections to receptors in the skin  - Motor connections to body muscles - Sensory and motor connections to internal body organs and gut   Functional organisation CNS - Mediates behaviour Somatic Nervous system - part of PNS - transmits sensation and produces movement - cranial nerves and spinal nerves Automatic Nervous system  - part of PNS - balances internal functions - Sympathetic - arousing - Parasympathetic - relaxing Enteric Nervous system  - controls gut   Anatomy and function of the Brain file:///home/chronos/u-e5c2a397a3d77f3868f00ca2c09225dc13341547/MyFiles/Downloads/Screenshot%202021-05-08%206.41.51%20PM.png The brain is an organ found in the skull of vertebrates Coordinating centre for sensation and intellectual activity Exerts control over behaviour Main divisions: Forebrain, Midbrain, Hindbrain Forebrain also known as Cerebrum Most complex and highly evolved part of the brain, responsible for most concscious behaviour Two hemispheres connected by corpus callosum  Outer layer = the Cerebral Cortex Occipital lobe - where visual processing begins, visual cortex Temporal lobe - hearing, language, Auditory cortex, Long-term memory Parietal lobe - Processing information about touch, somatosensory cortex, integrates sensory information from different modalities, spatial processing Frontal lobe - executive functions (planning, decision making), personality, motor cortex   Blood supply and Brain damage - Stroke - sudden appearance of neurological symptoms as a result of severely interrupted blood flow   Anatomy and function of the CNS: Subcortical structures The Limbic System  - the emotional brain - brouad functions include: emotional and sexual behaviours, survival mechanisms, memory, spatial navigation Principal structures:  - cingulate cortex - hippocampus - amygdala - hypothalamus   Hindbrain - "the old brain" -includes cerebellum, pons, medulla - reticular formation - coordinates information coming into and out of the spinal cord - also known as Brainstem - more primitive part of the brain, responsible for most unconscious behaviour Diencephalon - thalamus and hypothalamus Midbrain - tectum and tegmentum                                      

Historical background Cells of the brain are independent from one another structurally, metabolically, and functionally Information is transmitted from one neuron to the next across tiny gaps called Synapses   Neurons made up of Neuron, cell body, axon, and dendrites Sensory neurons Bring information into the CNS file:///home/chronos/u-e5c2a397a3d77f3868f00ca2c09225dc13341547/MyFiles/Downloads/Screenshot%202021-05-08%207.26.07%20PM.png Interneurons  Associate/connect sensory and motor activity in the CNS Motor neurons Send signals from the brain and spinal cord to muscles Neural networks - a functional group of neurons The Synapse - presynaptic neuron - prosynaptic neuron Language of neurons - excitation vs inhibition - summation of messages Neuron production and regeneration - CNS neurons with you for life - PNS neurons are able to rebuild axons Neuroplasticity  - Configuration of syanpses are constantly changing - Connections between neurons are 'plastic' therefore and be reformed   Glial cells Ependymal cell - small ovoid, secretes CSF Astrocyte - Star-shaped, contributes to neuronal nutrition, structural support and repair; contributes to forming blood-brain barrier and to healing scarring after injury, enhancment of brain activity by providing fuel to active brain regions Microglial cell - small, derived from blood; defensive dunction to remove dead tissue, aid in cell repair, scavenge debris in the nervous system Oligodedroglial cell - forms myelin around CNS axons in brain and spinal cord Schwann cell - wraps around peripheral nerves to form myelin   Conclusion - The nervous system comprises of two types of cell: neurons and glial cells                                    

Neural communiction

How do neurons process information? Electrical signals - Conducted within a neuron Chemical signals - Transmitted between neurons   Early research on electrical stimulation: Luigi Galvani (18th century) – electrical stimulation of dissected nerve induces muscle twitch. Gustav Theodore Fritsch and Eduard Hitzig (mid 19th century) – stimulation of (motor) neocortex in animals causes limb movement.  Roberts Bartholow (1874) – First report of human brain stimulation Slow flow - more frog experiments Helmholtz (19th century) Flow of information in the nervous system is too slow to be a flow of electricity Nerve conduction: 30–40 metres/second Electricity: 3 × 108 metres/second Instead, information travels along the axon as a wave of charge (Bernstein, 1886) Squid experiments Hodgkin and Huxley (1930s and 1940s) Experiments on the giant axon of squid Neurons have a natural electric charge - Resting potential Stimulation with electricity results in the conduction of an electric impulse along the axon - Action potential The resting potential  Difference in electrical charge across the cell membrane A store of negative energy on the intracellular side relative to the extracellular side Resting potential is approx. -70 mV Graded potential An increase of positive charge inside the membrane causes a depolarisation. An increase of negative charge inside of the membrane causes a hyperpolarisation. Graded potentials typically occur in the cell body (soma) Summation of inputs - Inputs from presynaptic neurons are either excitatory or inhibitory  Excitory inputs depolarise the membrane Inhibitory inputs hyperpolarise the membrane Firing of a nerve impulse determined by the summation of excitatory and inhibitory inputs The Action Potential An electrical impulse Large, brief reversal in polarity of an axon Lasts approximately 1 millisecond Threshold potential Voltage on a neural membrane at which an action potential is triggered Approximately -50mV relative to extracellular surround 3 phases of Action Potential Depolarisation phase Repolarisation phase Hyperpolarisation phase (Refractory period) file:///home/chronos/u-e5c2a397a3d77f3868f00ca2c09225dc13341547/MyFiles/Downloads/Screenshot%202021-05-08%207.56.23%20PM.png   Saltatory conduction an myeline sheaths Myelin - A fatty salty sheath that wraps around the axon Node of Ranvier - Part of an axon that is not covered by myelin - tiny gaps in the myelin sheath Saltatory conduction: Fast propagation of an action potential at successive nodes of Ranvier                                 Instead, information travels along the axon as a wave of charge (Bernstein, 1886)

Neurotransmitters and brain chemistry

Action potential - a rapid electrical signal that travels along the axon of a neuron Neurotransmitter - a chemical messenger between neurons e.g. serotonin, dopamine, glutamate etc.   Neurotransmitters often endogenous chemicals naturally occurring in the brain They can also be exogenous, meaning they can be introduced into the brain from the outside in the form of drugs such as THC, MDMA, alcohol. Endogenous neurochemicals Vast majority of these are neurotransmitters Neurotransmitters bind to 'receptors' on a neuron to influence its firing Neurotransmitters are released by neurons e.g. Dopamine is released by dopamine neurons Neurotransmitters bind to receptors Neurotransmitter = key; Receptors = lock When a receptor is bound by a neurotransmitter, it becomes activated This can either cause or inhibit action potentials (cell firing)   Types of Receptors Dopamine receptors: D1, D2, D3, D4 17 Serotonin (5-HT) Receptor: 5-HTIA, 1B, 1C, 2A, 2B, etc. 3 Glutamate Receptors: mGlur, AMPA, Kainate GABA receptors Norephinephrine (adrenaline) receptors Acetylcholine (ACh) receptors Serotonin (5-HT) 1A is inhibitory, while 5-HT2A is excitatory ex. Nicotine Releases dopamine into the brain. Dopamine is a monoamine neurotransmitter that signals for reward. When smoked, nicotine enters the blood stream, and makes its way into the brain in 7 seconds. Nicotine-Induced Dopamine Release occurs when dopamine are on neurons. When nicotine binds to the nicotinic receptors (nAChRs) on the dopamine neurons on the VTA/Ventral Tegmental Area, these neurons release dopamine into the NAcc/Nucleus Accumbens. This dopamine release gives the smoke the feeling of reward, which reinforces positive feelings associated with repeated smoking.                                  

Neuroimaging techniques

Neuroimaging techniques MRI - Magnetic Resonance Imaging Magnet - most important component, runs throughout the entire scanner, strength is measured using Tesla (T), 3T scanners are 30,000 as strong as the earth's magnetic pull; scanners are very expensive, cost rougly £1M per T. MRI is a medical technique used to: Create pictures of anatomy (structual MRI); To view functioning of the brain (Functional MRI) Structural MRI Meausres hydrogren protons in various tissue types These hydrogen protons spin at different rates in various tissue types Very complex  Smoking is associated with decreased prefrontal volume Functional MRI Can be used to determine which brain regions are important for various tasks Visual attention task - visual cortex activated Auditory attention task - activates the auditory cortex Decision-making task - activates the prefrontal cortex fMRI is used to measure brain function It does this by measuring levels of oxygen in the blood BOLD - Blood-Oxygen Level Dependent   Hemodynamic Response Function (HRF) Present a stimulus Oxygenated blood - rushes to the active region - peak is ~6 seconds after stimulus presentation Oxygenated blood then disappears Followed by a simultaneous increase in deoxygenated blood   Positron Emission Tomography Nuclear imaging technique Molecule ('ligand') is radio-labelled - usually with flourine-18 or carbon-11 - and injected  This 'radioligand' binds to certain receptors Gamma rays emitted from the ligand and detected by the scanner Areas of yellow and red show high binding, and thus high levels of receptors Receptors are important components of neurotransmitter systems Can image amount of receptors of various neurotransmitter systems Most common to examine dopamine receptors; easier to measure, dopamine dsyfunction is involved in many neuropsychiatric disorders Having less (or more) receptors indicates dysfunction in that neurotransmitter system Compared to non-smokers, smokers exhibit less dopamine in the striatum   Transcranial Magnetic Stimulations (TMS) - brain stimulation technique Is non-invasive Induces rapid and strong magnetic fields to induce a current in the brain TMS causes neurons under the site of stimulation to discharge an action potential  can cause long-lasting changes in brain function and behaviour TMS of the prefrontal cortex reduces Impulsivity                                

physical properties Basic anatomy of the eye and retina

Sensory Processing  The visual system is a sensory mechanism which gathers information about the environment and sends it to the brain via neural impulses. This is achieved by means of transduction. Transduction represents transformation of one type of energy into another. How does it work? The visual system responds  to a particular type of energy: Light Light energy is transduced into neural impulses via specialised receptor cells in the eyes. These receptor cells send electro-chemical messages to the neurons in the cerebral cortex. Light energy => chemical energy => electrical energy What is light? A narrow band in the spectrum of electromagnetic radiation capable of stimulating receptors in the eye. Three psychological dimensions of light Hue - determined by wavelength and roughly corresponds to colour names Saturation - relates to the purity of light (intense vs dull) If all radiation is of one wavelength, the colour is pure or saturated. If radiation contains all wavelengths, it has no hue- it is white. Brightness - relates to the amplitude/intensity of the radiation (light or dark) Anatomy of the eye Visual information is contained in the light relfected from objects. To perceive objects, we need sensory detectors that respond to the reflected light  As light passes through the lens of the eye, the image is inverted and focused to project on the back surface of the eye, the retina.  The retina and photoreceptors Retina contains several layers of cells including photoreceptors Photoreceptors respond to light energy by firing neural impulses There are two types of photoreceptor: CONES: provide most visual information and are responsible for colour vision RODS: more responsive in dim light. They are sensitive to black/white and shades of grey. The Fovea Region at the centre of the retina that is specialised for high acuity Receptive field at the centre at the eye's visual field Depression at the fovea where photoreceptors are packed most densely and where vision is clearest Acuity across the visual field Vision is better in the centre of the visual field than at the margins or periphery  When we look at the centre, letters at the periphery must be much larger than those in the centre for us to see them as well. The optic disc Region of the retina where axons forming the optic nerve leave the eye and where blood vessels enter and leave Has no photoreceptors and thus is a 'blind spot' From eye to brain Information from two retinal hemifields cross at the optic chiasm and travel to the opposite side of the brain. After this, most axons of the optic nerves project to the lateral geniculate nucleus  in the thalamus. Some project to the superior colliculus (sub-cortical pathway). Lateral geniculate nucleus (LGN) It is the main relay centre from the retina to the visual cortex It receives the information from the retinal ganglion cells but also, importantly, receives feedback from the cortex It performs a range of computations (spatiotemporal correlations) to achieve a 3D representation of visual space The primary visual cortex (V1) Also known as the Striate cortex because sections appear striped when stained Receives input from the LGN Basic processing of visual information Participates in the processing of form, colour and motion Hubel and Wiesel (1959) - single-cell recordings of electrical activity Most cells respond to best to lines or bars in a particular orientation in the visual field; some also respond to movement to any/specific directions The visual cortex is retinotopic Portions of the visual field are lawfully mapped onto areas of V1. Adjacent neurons process adjacent portions of of the visual field. Functional specialisation  The occipital cortex is composed of multiple regions Each region processes specific features of visual information V1 and V2 - basic visual processing V3 and V3a - form perception...

Theoretical approaches for visual perceptual system

Theories and illusions  Information encoded by the retina is complex and incomplete The visual system analyses different features and combines them into a meaningful. unified whole. How does it do this?  The Binding Problem Gestalt psychology Gestalt psychologists - Koffka, Kohler, Wertheimer (early 20th century) Theory of perceptual organisation - certain features of the sensory input are grouped together to form a whole, or Gestalt. Governed by innate principles:  Laws of proximity, similarity, good continuation, closure Law of Pragnanz Law of Prägnanz  A general principle that underpins all human perception. Of all the possible ways of interpreting the visual field and the objects within it, the simplest and most encompassing will be selected. In the previous examples the individual components, or parts, are grouped together to make a unified whole because it is the simplest interpretation Gestaltism in the real world Strengths: • Describes perceptual organisation well. • Principles have stood the test of time (though alternative laws have been suggested). Weaknesses: • More descriptive than explanatory. • Underestimated the importance of knowledge.   Constructivism Roots in philosophical empiricism Hermann von Helmholtz - perception as unconscious inference The modern constructivist approach Theoretical and experimental work conducted by, for example, Richard Gregory, Irvin Rock, and Arien Mack Shared assumptions: Perception is an indirect process of construction, guided by knowledge from experience.  There is an interaction of external and internal sources of information (e.g. expectations, motivations, emotions). Hypotheses and expectations can lead to errors producing visual illusions. 1. Ambiguous drawings demonstrate the phenomenon of expectancy Rat man Depednding on whether the participants had been exposed to line drawings of animals or faces in a previous series of slides, they reported seeing either a. a rat or b. a man wearing glasses. This is an example of how knowledge and recent experience influences interpretation of the data 2. Size constancy Our perception of an object's size remains constant despite variations in retinal size, i.e. sensory input The sensory input does not provide information about the true size of the object in space Objects of different heights at different distances can subtend the same degree of visual angle on the retina Objects of the same height at different distances subtend different degrees of visual angle on the retina Size must therefore be inferred from cues to distance The perception of distance and depth The perception of distance in a three dimensional world is not straightforward as retina codes input in just two dimensions Constructivists argue that we learn to infer distance on the basis of multiple cues that have become associated with each other through experience and learning i.e. Knowledge of the dimension is acquired by associating different visual and kinesthetic cues Binocular disparity (binocular cue) Your eyes are about 7cm apart and this distance guarantees that the two eyes will have slightly different views of the world whenever nearby objects are at different distances Judging depth binocularly is known as stereopsis Vergence (binocular/oculomotor cue) The eyes converge or move together to look at nearby objects and diverge or move apart to look at far away objects Accomodation Involves information provided by muscles that control lens shape. There is a change in the shape of lens in your eye as you focus on objects at different distances (thin lens for distant objects; thick lens for nearby objects). Autostereogram a 2D image and yet it can be viewed as a 3D image when there is a dissociation of vergence and accomodation. Look past the image and then try to focus without allowing the eyes to converge on the image (which they will naturally do). Viewing the 3D image requires...

How disorders of vision reveal workings of the brain

Functional specialisation in the 'visual' brain Scientists have identified multiple specialised visual processing areas in the human occipital cortex Brain imaging studies Brain imaging evidence is correlational What is wrong with these statements? Presence of bear patrol + absence of bears = bear patrol working like a charm Presence of rock + absence of tigers = rock repels tigers Processing of colour stimulus + increased blood flow area V4 =V4 responsible for colour perception Neurological evidence Brain imaging studies indicate that the processing of specific features of visual information (e.g. colour, motion, faces) is associated with activity in specific areas of the brain (e.g. V4, V5, FFA) BUT they do not show clearly that these areas are necessary for perception Additional evidence that these areas are of major importance for specific types of perception comes from neurological studies on patients with various visual disorders Achromatopsia There are rare neuropsychological cases where patients have lost their colour vision, with other visual attributes remaining intact Heywood and Kentridge (2003) concluded that damage to area V4 is often involved  Achromatopsia patients lose the ability to disinguish differences in hue, but retain some ability to discriminate brightness/reflectance Akinetopsia Extremely rare cases exist where patients suffer motion blindess, such as patient LM. Perception was akin to viewing the world as snapshots. Colour and form perception were intact, but the ability to judge the direction and speed of moving objects was severely impaired Caused by damage to area V5 (referred to as MT in monkeys) in the visual cortex - located in occipital lobe of the brain Supports brain imaging evidence that this area is specialised for the processing of motion Prosopagnosia The inability to identify people on the basis of their face Cause by damage to the left or right fusiform gyrus, located in lateral occipital and temporal lobes of the brain Suggests that this area is specialised for the processing of faces Individuals use other information to identify people: body, clothes, voice, context, etc. Visual Agnosia The inability to percieve and/or recognise an object by sign (in the absence of any visual or intellectual impairment) In apperceptive Agnosia, individuals cannot bind together lines and basic shapes to form an integrated percept of an object In associative Agnosia, an integrated percept is formed, but has no meaning Dorsal = how stream Ventral = what stream Visual agnosia caused by damage to the lateral occipital and/or temporal lobes of the brain We can infer that these areas of the brain are involved in: The generation of a visual object as a discrete percept The connection between the perception of an object and associated contextual information such as object's name and function Blindsight Patients with damage to the primary visual cortex following a stroke are unable to detect objects within portions of space  areas of blindness are called a Scotoma Sometimes the patient may be able to fixate of look straight at, or even point to, a visual object in the affected visual field, even though they do not consciously "see" the object.  Patient D.B. A light beam was projected to one of 7 locations within his scotoma Upon hearing a tone, DB was required to move his eyes to that location. In control conditions, no target was illuminated DB reported seeing nothing within his scotoma and saw both conditions as identical, but still managed to move his eyes to the appropriate location Cortical vs. Subcortical Pathways 90% of neural connections from the eyes run to area V1 in the visual cortex via the lateral geniculate nucleus (LGN) Most of the remaining 10% connect directly to a sub-cortical structure called the superior colliculus - this pathway was intact in DB's brain A primitive Visual system This neual pathway to the superior colliculus might...

Relationship between the physical properties and perceptual attributes of sound

Functions of hearing monitoring important signals alerting communication well-being in the broad sense Physical properties of sound Frequency - the number of cycles per second Amplitude - the pressure of the wave (intensity) The perceptual attributes of sound Pitch - corresponds most closely to frequency Loudness - corresponds to amplitude Timbre - perception of sound quality, corresponds to the complexity of a sound The Auditory system Peripheral auditory system Central auditory system Component parts of the human ear file:///home/chronos/u-e5c2a397a3d77f3868f00ca2c09225dc13341547/MyFiles/Downloads/Screenshot%202021-05-09%208.22.43%20PM.png   The auditory cortex is located in the temporal lobe The primary auditory cortex is mapped tonotopically Functional specialisation in 'higher' auditory areas Processing is hierarchal Functional lateralisation Hearing loss and deafness 3 main causes:  Conduction deafness - disorders of the outer and middle ear that prevent sounds from reacing the cochlea Sensorineural deafness - originates from cochlear or auditory nerve lesions Central deafness - hearing loss caused by brain lesions (such as stroke), with complex results e.g. Cortical deafness (Graham, Greenwood & Lecky, 1980) Treatments for deafness Auditory perception underlies a number of important functions (alerting, orienting, communication) Auditory system is complex, sophisticated and challenging (for us researchers) It is also sensitive and must be looked after- especially in the era of personalised music                                

To know some of the history of research on learning To know the basic elements and principles of classical conditioning To become familiar with fear conditioning To know some applications of classical conditioning

Behaviour and adaptation Survival of a species requires members to behave in a way that is adapted to their environment Behaviour can be adapted in two ways: Through evolution Through learning Dimension of behavioural plasticity Learning is a crucial activity in human culture The human capacity for learning is unmatched by that of any other living thing What is learning? The process by which long-lasting changes occur in behavioural potential as a result of experience two major types of associative learning; Classical conditioning Operant conditioning History of research on learning Edward L. Thorndike (1898) - Instrumental learning Puzzle boxes. Ivan Pavlov (1904) - Classical conditioning; Pavlov's dogs John B Watson (1920) - Fear conditioning, Little Albert B. F. Skinner (1938) - Operant conditioning, Skinner boxes Albert Bandura (1961)- Observational learning, Bobo doll   Classical (Pavlovian) Conditioning First studied by Ivan Pavlov (1904) Occurs when a previously neutral stimulus acquires the ability to evoke a particular response originally evoked by another stimulus, through pairing Types of associative learning: An association is made between two stimuli, leading to a transfer of effect from one to the other Elements of Classical Conditioning 1. Before conditioning: Unconditional stimulus -> unconditioned response 2. Before conditioning: Neutral stimulus -> No conditioned response 3. During conditioning: Conditioned stimulus + unconditioned stimulus -> Unconditioned response 4. After conditioning: Conditioned stimulus -> Conditioned response   Fear conditioning A form of emotional learning in which a neutral stimulus comes to elicit defensive behaviour and physiological responses after being associated with an aversive event Watson and Rayner (1920) Wanted to demonstrate that it was possible develop general explanations of complex human behaviour based on classical conditioning principles Set out to see if a child could be classically conditioned to experience a strong emotional reaction - fear - 'Little Albert' Little Albert Successfully conditioned Little Albert to fear a white rat Fear response was generalised to other similar stimuli such as a white beard Demonstrated that a relatively complex reaction could be conditioned using Pavlovian techniques Controversy Surrounding study The neural basis Experiments with rats showed that conditioned fear responses cease when links between the amygdala and other areas of the brain are severed Supporting evidence and brain-imaging studies suggests that the amygdala plays a critical role in fear conditioning (Phelps & LeDoux, 2005) Applications of classical conditioning Predation control Exposure therapies Advertising                                          

Reinforcements from the environment

Instrumental learning Edward Thorndike (1898) - experiments investigating 'instrumental' behaviour (voluntary, active behaviour that affects the environment) Placed a hungry cat inside a puzzle box and small amount of food outside the door Measured the time taken to escape over a number of trials Findings and conclusions Learning more gradual than might have been expected Not due to insight or understanding, but through formation of an association between stimulus and response Law of effect: behaviours that are followed by a 'satisfying state of affairs' tend to be repeated and those that produce an unpleasant state of affairs are less likely to be repeated operant conditioning B.F. Skinner (1983, 1953) Developed Thorndike's research Operant behaviour: behaviour that an organism produces that has some impact on the environment, which in turn changes because of that impact Environmental changes either reinforce or punish the behaviours that produced them Operant conditioning chamber (Skinner box) A controlled environment for studying the behaviour of small organisms  Behaviour such as pressing the lever is either reinforced or punished in the presence of a discriminative stimulus The consequence of behaviour is the presentation or removal or a desirable or aversive stimulus (food or shock) Discriminative stimulus > operant behaviour > consequence Frequency of responses measured over time Reinforcement Positive Reinforcement Presentation of a desirable stimulus following a response Lever press (operant behaviour) -> food (consequence) The consequence of food leads to an increase in lever pressing E.g. reward after handing in a lost item Negative reinforcement Removal of an aversive stimulus following a response Lever press (operant behaviour) -> Escape to avoid shock (consequence) The consequence of escaping the shock leads to increase in lever pressing E.g. Pain relief/prevention after taking an aspirin Punishment Positive punishment: Presentation of an aversive stimulus following a response Negative punishment: Removal of a desirable stimulus following a response Primary reinforcers/punishers: Do not need to be learned, gain their functions from biological mechanisms Secondary reinforcers/punishers: Are not innately effective and need to be learned. typically acquire their effectiveness through pairing with primary reinforcers/punishers Reinforcement vs Punishment Thorndike observed that punishment was relatively ineffective, and believed reinforcement to be critical to learning Punishment might be effective in stopping a behaviour, but it doesn't specify what the desired behaviour Learning is thus usually more effective through reinforcement of the desired behaviour, rather than punishment of the unacceptable behaviour Schedules of reinforcements Different schedules of reinforcement produce different rates of responding Continuous reinforcement: reinforce every time behaviour occurs rapid learning - rapid extinction Partial/Intermittent reinforcement Sometimes reinforce, sometimes don't  Slower learning; more resistant to extinction interval and ratio schedules   Shaping - involves rewarding successive approximations of the target behaviour Project Pigeon - During WWII, Skinner used operant conditioning to train pigeons to guide missiles. Animal behaviour enterprises used operant conditioning to train animals for commercial purposes opened the IQ zoo in 1955 never used punishment, only positive reinforcement Later developed programs for people with intellectual and developmental disabilities                                        

Key memory stages Encoding - info transferred into memory Storage - maintenance of info Retrieval - remembering info (recall vs recognition memory) Multi-store Model of Memory  Input -> Sensory Store (Iconic, Echoic) -> Short term store (rehearsal, coding, decisions, retrieval strategies) <- >Long term store (Permanent memory store)                                                - Output   Atkinson and Shiffrin (1968) Sensory store - brief holding of info, modality specific Short-term store - limited capacity, temporary Long-term store - unlimited capacity, near permanent Assumptions: Info transferred to and form LTS through STS only STS and LTS and unitary The longer an item is held in STS. the greater the chance it will be transferred into LTS Sensory stores Stimuli reside very briefly in sensory store This fades rapidly but info can be transferred to short term store by maintenance  and rehearsal Iconic store - visual sensory stimuli Echoic store - auditory sensory stimuli Iconic store, memory lasts 0.5 seconds most influential work in this area by Sperling (1960) Brief presentation of rows of letters, read as many as possible participants could only report 4-5 letters Assumed visual info faded before most of it could be reported Echoic store, lasts 0.2 seconds transient auditory store Auditory suffix effect   Short term store Limited capacity Material can only be maintained in store with rehearsal Unitary Info transferred to and from LTS through STS only The longer an item is held in STS, the greater the chance it will be transferred into LTS Immediate memory span is 7 plus or minus 2 The Brown-Peterson Paradigm If rehearsal is needed to maintain info in store, preventing rehearsal should impair memory Murdock (1961) wanted to measure the rate of decay from STS: Read either one word, three words, or three consonants (trigrams) to participants Count backwards in 3's for different duration of times rehearsal is necessary for maintenance of info in STS with enough rehearsal, info enter the LTS Long term store has unlimited capacity  near permanent storage of info Unlimited duration  can remember info from years ago Double dissociations - two tasks involve different stores if they are affected differently e.g. X performs normally on tasl A but poorly on Task B, Y performs poorly on task A but normally on task B   summary STS  - limited capacity - digit span plus/minus 7 - needs rehearsal - forgetting LTS - unlimited capacity and duration - separate from STS - serial position effects and double dissociations Problems for model Patient KF: Impaired STS but normal LTS some normal, some impaired STM Conclusions Multi-store model very useful conceptually: Memory is not one whole entity 3 different sub-structures: SS, STS & LTS.  A lot of evidence supports distinction between and within these structures: SS: info decays very rapidly, visual vs. auditory info STS: limited capacity, rehearsal required LTS: separate from STS. Model problems: - STS not unitary - Impairment in STS doesn't always lead to impairment in LTS - Model is too simplistic - A better model is needed to explain the STS                                      

WORKING MEMORY MODEL - BADDELEY, 2000 Central Executive - general system resembling attentional control (most important component) Phonological loop - processing + brief storage of speech-based information Visuo-spatial sketchpad - spatial and visual processing + brief storage Episodic buffer - temporary storage for integrated information from phonological loop, visuo-spatial sketchpad and long-term memory   The Phonological loop keeps speech-based info for 1-2 seconds Articulatory Control Process translates visual info into speech-based info transfers this info to phonological store refreshes info in store to prevent decay Word length effect short word recall > long word recall effect due to slower rehearsal of long words evidence shows articulatory suppression eliminates word length effect AS involves loop and hence causes disruption in word span task loop determined by temporal duration Irrelevant speech effect - Salame and Baddeley (1982) Irrelevant speech effect -> recall declines Supports assumption that loop uses speech-based rehearsal processes Suggests if irrelevant material not speech-based, effect should disappear The Visuo-Spatial Sketchpad temporary storage and manipulation of visual and spatial info Visual cache - stores info about visual form and colour Inner scribe - Deals with spatial and movement info Rehearses info in the cache Transfers info from the cache to central executive Spatial task = activation of right hemisphere visual task = activation of left hemisphere Most tasks use both components of the VSS     The Central Executive most important part of the working memory model supervises the 2 slave ssytems (loop +vss) function include Planning/organising  Inhibition Switching retrieval plans dual-task performance selective attention thought to be located in the frontal lobes   Summary There is a lot of evidence to support CE (random number generation, stroop effect, dual tasking) Contrasting evidence of CE location in the brain Lack of general storage component in the Model (loop +VSS process/store specific info only); CE = general processing Episodic buffer Integrate info from range of sources (loop/VSS) into a single episode Hence acts as a buffer capacity of EB is about 4 chunks Episodic buffer should enhance memory when different kinds of information need to be integrated Baddeley and Wilson (2002) study on EB: Compared amnesiacs with or without deficient CE Immediate prose recall was higher in those with efficient CE Supports need of normal CE for normal EB performance However, they:  used the same group of amnesiacs Additional central executive task Same detriment on both groups Doesn't support need of normal CE of EB performance   WM model improved by the addition of EB: general storage facility was needed buffer between loop and VSS needed EB can store more info than the slave systems More research is needed to determine: how does info from loop and VSS combine to form 1 unit in EB? How does info from other sensory modalities (touch, smell) get stored in EB? Conclusions Working Memory Model better than multi-store model as: can explain specific deficits in STM can explain impaired STM with normal LTM CE role not entirely understood More work needed to understand the EB, especially in patients Working memory deals with information on a short term basis                                        

Long term memory  Non-declarative memory Declarative memory Permanent/near permanent storage of info Info has been well processed and integrated Assumed to be of unlimited capacity and duration, unlike STM Encoding  Consolidation hypothesis Some information is stored temporarily in STM With rehearsal, information transfers to long-term memory This transfer = consolidation Rehearsal -> neural activity causing structural changes These changes are permanent/solid and are responsible for LTM Non-declarative Unconscious/implicit memory Highly automised procedures Demonstrated through behaviour Skill learning, priming - triggering of specific memories by certain cues, facilitated processing of a stimulus by presenting the same or similar stimulus previously conditioning - triggering of behaviour by certain cues Declarative - conscious memory, explicit recollection of events and facts Semantic memory - memory relating to general knowledge Episodic memory - memory for events and episodes Implicit memory - revealed when performance on a task is facilitated in the absence of conscious recollection Explicit memory - is revealed when performance on a task requires conscious recollections of previous experiences Way to test LTM - Non-declarative = implicit test, subjects are not aware of their memory being tested - word fragment completion Declarative = explicit test, subjects are aware that their memory is being tested - recall, cued recall, recognition Summary: There is evidence for at least 5 types of LTM Memory  is not unitary Distinction is supported a behavioural and neuropsychological level All explicit memories are not the same Some memories are easier to recall than others Levels of processing effect -> deep/semantic processing boosts memory Encoding specificity principle -> retrieval cues boost memory Context-dependent memory -> encoding and retrieval match boosts memory                                        

1. Transience Forgetting over time Affects sensory storage Affects short term storage Affects long term storage Memories don't fade at a constant rate Early on = detailed memory Later on = generic memory 2. Absentmindedness Lapses in attention that cause forgetting It occurs because good memory needs full attention Distraction = divided attention causes encoding issues which mean weaker memory traces not always a bad thing; automatic pilot is cognitively economical,  can lead to issues in remembering the past and remembering to do something in the future 3.  Blocking Momentary inability to retrieve info Tip of the tongue experience Blocking happens mainly for names of people and places because their links to related concepts are weak 4. Persistence Remembering unwanted memories Occurs after traumatic event Persistence of intrusive memories Real life emotional amplifies emotional enhancement effect emotion focuses our attention - elaborate encoding - better memory for central themes Real life emotional trauma is associated with strong emotion Heightened amygdala response; greater peak and for longer time related to fight or flight survival 4 sins of memory occur at different stages of the memory process Transience > storage absentmindedness > encoding blocking > retrieval persistence > retrieval these are also forgetting errors Transience - forgetting over time Absentmindedness - lapses in attention that cause forgetting Blocking - momentary forgetting info Persistence - not being able to forget unwanted info 5. Memory Misattribution confusing the source of memory correct recall of info but memory fails in determining where/when/how the info was encoded Why does it occur? error in: Internal source monitoring - what i did vs what i thought i did External source monitoring - who told me that piece of info Reality source monitoring - actual event vs imagined event False memories in the DRM paradigm occur because the absent word is strongly related to all the other words As  each word is read, this createsa a sense of familiarity for the missing word False memories in the lab and the real world are a strong feeling of familiarity for something that didn't happen 6. Suggestivity Incoporating misleading information into a memory Suggestibility also occurs outside the laboratory - flashbulb memories We do not store all details of our experiences  memory is therefore vulnerable to disruption/suggestibility different to misattribution as needs external disruption to occur 7. Bias The influence of knowledge and beliefs on recollection of the past Memory is reconstructed rather than replayed Memoy is therefore influence by your current state of mind 3 types of memory bias 1. Consistency bias - changing the past to fit the present 2. Change bias - exaggerating differences between past and present 3. Egocentric bias - distorting the past to make us look better                                  

Amnesia - any loss of memory Psychological vs Physiological factors:  Organic amnesia Infantile Amnesia Repressive amnesia Temporal factors: Retrograde amnesia Anterograde amnesia Causes of Amnesia Stroke Closed head injury Herpes simplex encephalitis Anoxia Korsokoffs syndrome, due to chronic alcohol abuse Major brain structures involved Diencephalon (subcortical region) - Korsakoffs Medial temporal lone (cortical region) - due to anoxia   Summary STM appears relatively normal in many cases of amnesia, but exceptions exist LTM can be divided into implicit vs explicit memory Amnesic patients appear to show normal performance on implicit tests Amnesic patients are impaired on explicit tests Aggleton and Brown (1999) 2 distinct memory systems originating within the medial temporal lobe - Hippocampal system - subserves process of recollection (remember) - Perirhinal system - subserves process of familiarity (know) Recognition memory based either on: - Remembering - contextual recollection - Knowing - familiarity, no contextual detail Key hypotheses:  damage to both systems - Impaired R + F Damage to hippocampus only - impaired R only                                    

Brandt, K.R., (2016). Forgetting. In S. Groes (ed.), Memory in the Twenty-first Century: New Critical Perspectives from the Sciences and Arts and Humanities. Palgrave Macmillan.

WIlliam James (1890) saw selectivity as the hallmark of attention. Selective attention is still the focus of most modern research on attention Selective attention - refers to the ability to focus attention on a specific stimulus, such as an object, location, or message Limits to what we can perceive Mack and Rock (1998) carried out research on: inattentional blindness: failure to notice an unexpected object that is clearly visible change blindness: failure to notice a change in a visible object These failures are not to do with vision deficits, but rather limits in perceptual processing capacity and lack of atention Why do we need selective attention? Unless we pay attention, we are not aware of what we see of hear We sometimes overlook our friends in a crowded room, and sometimes fail to notice when a friend gets a haircut Selection must take place to focus our limited capacity cognitive processing resources on a subset of information and ignore the rest Early selection - selection takes place at early stage of perception with limited processing of ignored inputs Late selection - selection takes place at late stage of perception with extensive processing of ignored inputs Broadbent's (1958) FIlter theory of selective attention Broadbent's interest was fuelled in part by his knowledge of the problems faced by radar operators in WWII They would be required to listen to and communicate with several different pilots whose voices were being relayed over a single loudspeaker all at once Broadbent proposed that attention acts as an early selective filter to prevent information at a late stage of processing This filtering occurs by selecting relevant information on the basis of simple physical properties during an early stage of processing Support for Broadbent's model Broadbent (1958) investigated the extent to which we process unattended information under experimental  conditions using 'selective shadowing' In the unattended ear - participants failed to notice a complete change in the language spoken Participants did notice switch from male to female or switch from speech to 400 Hz tone  Spering (1960) showed that participants typically report 4/5 items from brief visual arrays containing 12 items - a clear demonstration of limited capacity processing Von Wright (1970) showed that physical cues were more effective in allowing selective report than semantic cues - thus attentional selection operates on basic physical features - evidence for early selection Problems for Broadbent's model  'shadowing' studies often used retrospective questioning e.g. surprise questions about a non-shadowed message at the end of shadowing Deutsch and Deutsch (1963) Late Selection Theory Parallel processing of all inputs to the point of full semantic analysis  Selection is based on the importance or relevance of stimuli The bottleneck in processing is placed after semantic analysis but before entry into awareness and memory-based systems for the control of behaviour Support for Deutsch and Deutsch Mckay (1973) -Participants favoured the interpretation of the sentence suggested by the unattended/unshadowed word Von Wright, Anderson and Stenman (1975) Certain words were paired with electric shocks Because of conditioning , the words then caused a fear response presented on their own, measurable by galvanic skin response or GSR. using the selective shadowing task, Von Wright and colleagues found that conditione words and synonyms of these words in the ignored ear still produced GSR reponses, even without awareness They concluded that some meaning must be processed from the non-shadowed message and that Broadbent's model cannot be entirely correct Tipper (1985) Negative priming effect - participants show slower reaction times for recognising an object if that object has been previously ignored Unattended visual objects may undergo full perceptual processing and object recognition but then be actively...

Perceptual load theory (Lavie, 1995) Can explain the contradictory early and late selection findings sometimes selection is late and sometimes it is early - it depends on the perceptual load Perceptual load refers to the amount of perceptual processing that has to be undertaken The theory retains the early selection notion that perceptual systems can't process all the information available to the fullest extent and that attention is the means of selecting a subset of the information available for detailed processing if processing of information selected is not perceptually demanding, then spare processing capacity is unintentionally and automatically allocated to other available information High perceptual load - many resources are used for a perceptually demanding task and thus few are available to process ignored inputs Low perceptual load - few resources are used to a perceptually non-demanding task and thus many are available to process ignored inputs Neuroimaging research - high perceptual load reduces or eliminates neural activity related to distractor perception   Some criticisms of the PLT - Perceptual load is what perceptual load tests test, there is no clear refutation for perceptual load - Dilution effects - many experiments manipulate load by varying the number of items in the display. Low load conditions tend to have few distractors whereas high load conditions tend to have multiple distractors. The interference from one specific distractor may be diluted by the presence of the other distractors   The efficiency of selective attention is dependent not only on perceptual load but also on cognitive load   Load theory of Selective attention and Cognitive control Lavie (2004, 2010) theorised that executive functions are necessary are attentional selection under low p-load conditions We use executive control to inhibit distractor stimuli We can vary the availability of executive processes (and therefore out inability to inhibit distractors) by manipulating cognitive load An alternative view Some evidence indicates that cognitive load in fact reduces susceptibility to distraction Sorqvist and Marsh (2015) propose that cognitive load shields against distraction by a. reducing undesired processing of distractors and b, enhancing events/stimuli within the focus of attention                                          

Space-based attention Spotlight analogy Hermann von Helmholtz (1894) Centrally fixed gaze Part of screen illuminated by electric spark Individual could discern letter if attention was directed towards that region prior to the spark First demonstration of covert attention - a shift of attention without moving the eyes or head Zoom lens theory Modification of spotlight approach area of focal attention can be adjusted in line with task demands Spatial attention may not be restricted to a single circular area The focus of attention can also move instantaneously from one location to another without a cost for the amount of distance travelled Visual spatial atetention is clearly more flexible than the spotlight or zoom lens models would predict. However, the general concept of 'space-based attention' is still fundamental Evidence for space-based attention from studies of disorders of attention damage to the right hemisphere - especially within the parietal lobe - often leads to symptoms of the neglect syndrome  Patients fail to acknowledge that objects or events exist in the hemispace opposite to their lesion Neglect for the left side of space is more common than neglect of the right side of space. This is likely because the right hemisphere represents left and right space, whereas the left hemisphere tends to represent right space alone (Mesulam, 1999) Spatial neglect - Neglect patients tested on Posner's cueing tasks have difficulty orienting attention to the neglected side - Neglect patients have particularly difficulty disengaging attention - Neglect patients with Parietal damage only can still process illusory figures that are connected by subjective contours, suggesting that the grouping features in the neglected visual field may occur despite apparent spatial neglect Visual Extinction - similar to visual neglect; it is the failure to consciously perceieve of respond to a stimulus that is on the opposite side of the lesion when presented simultaneously with a stimulus that is on the same side as the lesion Pseudoneglect in neurotypical individuals - In a non-lesioned brain there is an attentional bias for the left side of space   Object-based attention Attention is directed not only to spatial locations but also to perceptual objects When viewing natural scenes, eye moevements are directed almost exclusively to objects Attention can be directed to objects independently of regions of space Attention to face: activation in fusiform face area Attention to house: activation in parahippocampal place area Attention to visual motion: activation in area MT/MST Attention prioritises objects over regions of space - It is easier to judge two attributes belonging to one object than the same two belonging to different objects, even though the spatial distance between the two attributes is the same in both cases                                  

Psychopharmacology - the study of the effects of drugs on the nervous system and on behaviour Pharmacotherapy - treatment of illness by drugs - not just psychological Pharmacokinetics - process by which drugs are absorbed, distributed in the body, metabolised and excreted Drugs can act at several different sites and have different effect - psychopharmacology looks at effects on CNS Pharmacodynamics: effects of drugs on target, e.g. 'Therapeutic Index': the ratio between the dose that produces the desired effect in 50% of the animals and the dose that produces toxic effects in 50% of the animals Repeated drug use usually produces tolerance (reduced effectiveness) and withdrawal effects, but occasionally causes sensitisation Drug studies need to have a control condition - usually inactive placebo - allows for admin, expection, etc.   Influences on Pharmakinetics 1. Mode of administration How the body eliminates drugs  - Drugs are broken down in the kidneys, liver, and intestines - Drugs or metabolites are then executed in urine, faeces, sweat, breast milk, and exhaled air - Some drugs only become fully active when metabolised to a secondary form - Some substances that cannot be removed may build up in the body and become toxic Blood Brain Barrier (BBB) Peripherally administered drugs vary in how easily or even if they can enter the brain - due to the BBB BBB is formed from tightness of capillary wall cells and also surrounding glial cells or astrocytes Fat-soluble drugs pass quite easily through the cell membrane lipid layers Many substances need active transport across the cell membranes Capillaries - capillaries in the brain have tight junctions and are covered with astrocyte feet. These properties prevent materials from moving in and out easily Areas of the brain known to have weak BBB: Pituitary gland Pineal gland Area postrema Neurotransmitter receptors Receptors are protein complexes which can selectively bind neurotransmitter molecules and send a signal in the target cell Surface cell receptors can be divided into two large families: receptor-regulated ion channels or ionotropic receptors G protein-regulated receptors or metabotropic receptors (slow acting) Types of Drug action Agonist - drug that enhances/mimics action of neurotransmitter NT could be excitation or inhibition of postsynaptic cell Antagonist - drug that block/inhibits action of neurotransmitter Direct action - binds with receptor and mimics activiation or prevents activation by natural NT Indirenct action - binds to separate site on receptor that does not interfere directly with natual NT/ligand binding                              

Schizophrenia Type 1: Delusions Hallucinations Disorganised speech Disorganised behaviour;agitation Type 2: Catatonic behaviour Blunted emotions; loss of interest Appears during adolescence/early adulthood Neurobiology of SZ Numerous brain abnormalities Enlarged ventricles thinner cortex poorer blood flow to prefrontal cortex loss of neuronal connections disorganised neurones in hippocampus changes in dopamine, glutamate, GABA and their receptors 'Dopamine hypothesis' of SZ Overuse of amphetamine found to produce symptoms like paranoid SZ in mid-20th century As amphetamine enhances dopamine activity, thought SZ is related to overactive dopamine Early antipsychotic drugs in part blocked DA receptors Antipsychotic treatment Tardive dyskinesia - involuntary spasms and facial distortions from long-term antipsychotic use - often wrongly associated with madness rather than the treatment Clozapine - fewer motor effects, but other side effects include blood cell damage and weight gain Mood disorders: Major Depressive Disorder/MDD prolonged loss of interest, feeling worthless, guilty, disrupted sleep and appetite may also be associated with considerable anxiety often considere to be two types of depression 1. endogenous - no obvious cause. 2. reactive - may result from stressful life events patients diagnosed to these categories do not appear consistently different, either in aetiology or treatment response Primary depression - no obvious cause Secondary depression - caused by another disorder Bipolar disorder (manic depression) alternation between depression and intense excitation (mania) - cycle period varies greatly across people During mania (days to months) - hyperactive, change plans without completion, overconfident, insensitive to others, often leave broken relationships in their path. Treatment of depression Mid-20th century: Monoamine Oxidase Inhibitors - prevent breakdown of NA, DA, 5-HT Tricyclis antidepressants (TCAs) - NA and 5-HT uptake inhibitors and other actions Selective Serotonin Reuptake Inhibitos - Prozac; more selective than TCAs thus fewer side effects - but not necessarily more effective SNRIs - Serotonin and Noradrenaline Reuptake Inhibitor Drugs dont work at all for 20% of psychotic patients Electroconvulsive therapy noticed that psychotic patients improved after epileptic attacks Simulated by electric shock to head  improves depression and BD more quickly than drugs-usually used when drugs dont work Long-term use may damage memory, but may recover Psychosurgery is another option, as well as deep-brain stimulation; Vagus Nerve Stimulation; Transcranial Magnetic Stimulation Treatment of Bipolar disorder ECT and TMS Anticonvulsant drugs show promise Lithium - chemical effective in suppressing mania, without preventing normal emotions Treatment of Anxiety disorders Generalised Anxiety Disorder  Baribiturates - highly addictive and not very safe Benzodiazepines - indirect agonist for the GABA receptor; these drugs are used for their tranquilizing effects, can be used as sleeping pills, but much safer. Valium and Librium Selecitve-hypnotic drugs like alcohol or barbiturates act like GABA, causing increased chloride conductance  Antianxiety drugs (benzodiazepine) enhance the binding of GABA Because of their different actions, these drugs should not be taken together. - Sleeping pills/anxiolytics with similar drugs or alcohol should not be mixed.   Many drug treatments are hardly more effective than placebo, but may be most useful when combined with psychotherapy.   EVOLUTIONARY PSYCHOLOGY Human behaviour, thoughts and feelings can be understood by considering which behaviour, thoughts and feelings increased relative survival and reproduction Certain behaviour, T&F increased ancestral humans' abilities to have more offspring than less successful humans The offspring of these individuals inherited the genes coding for the same behaviour, T&F Sexual selection Special case...