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Introduction and BackgroundWhat is cognition?Understanding cognitive processes provides a framework for understanding all other branches of psychology.One definition of cognition“ .. term “cognition” refers to all processes by which the sensory input is transformed, reduced elaborated, stored, recov...

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Introduction and Background What is cognition? Understanding cognitive processes provides a framework for understanding all other branches of psychology. One definition of cognition “ ...the term “cognition” refers to all processes by which the sensory input is transformed, reduced elaborated, stored, recovered, and used.” Ulrich Neisser, 1967. Neisser goes on to point out that given such a definition “ it is apparent that cognition is involved in everything a human being might possibly do; that every psychological phenomenon is a cognitive phenomenon” Some very brief history …. Introspectionists: Studies interesting things, but with poor methodology. Behaviourists: had a very strong methodology (emphasis on the observable), but studies less interesting things… Gestalt theorists: Resurrected mental processes as a viable object of study ( but were a bit vague..) Cognitive psychology: began to emerge during the 1950s as computer systems have psychologists a new metaphor for the mind.

The information processing metaphor: • Mental processes intervene between the presentation of a stimulus and the production of a response • These processes operate on information which must be encoded in some form (symbolic representations). • These processes take time which is why cognitive psychologists’ favourite DV (dependent variable) is reaction time!

• Information processing systems have a finite capacity • Concepts such as storage / retrieval / transformation can be applied to information processed by brains and computers. Methodological approaches There are four approaches to testing models of cognitive function: 1) ● ● ●

Experimental Psychology Psychological experiments with healthy humans Typically involve reasonably large sample sizes and small budgets… Traditional inferential statistics (with inferential statistics you take data from samples and make generalisations about a population- for example stand in a mall and ask 100 people if they enjoy shopping there) used to determine success.

Typical example : State dependent learning (e.g. Godden & Baddley, 1975) Material learned while diving is better recalled when diving. 2) Computational Modelling ● Computer simulations of cognitive processes ● Often involving parallel distributed processing (PDP/ neural networks)is based on the idea that the brain does not function in a series of activities but rather performs a range of activities at the same time, parallel to each other Typical example: McClelland & Rumelhart’s PDP model of world recognition 3) ● ● ●

Cognitive Neuropsychology/ Neuropsychiatry Studying the consequences of brain damage/ psychiatric disorders on cognitive function Single cases can be important Associations/ Dissociations used to reveal the “modularity of the mind”.

Typical example: Dissociation between acquired dyslexia and acquired anomia. TMS (Transcranial Magnetic Stimulation) opening new avenues for research.

4) Cognitive Neuroscience ● Studies how the brain implements cognitive functions, often using expensive neuroimaging technology ● EEG/MEG/TMS/PET/fMRI ● Sophisticated techniques required to interpret data. Typical example: Are different regions of the brain involved when naming pictures and reading words? (Yes...) Beware of being swayed by fancy pictures (McCabe & Castel, 2008) TOP-Down vs. Bottom-Up Processing Information processing models often assume a “bottom up” approach : input proceeds through a series of processing stages until the required output is produced. It is processing that is directly influenced by environmental stimuli. IN REALITY “ top down: influences are enormous ( but much harder ti model): They include goals, expectations, desires, beliefs, plans, interventions etc. It is stimulus processing that is affected by internal factors such as the individuals past experience and expectations. (e.g. PARIS IN THE SPRING not SPRING IN THE PARIS triangle) Eye movements reflect both: Influenced both by external stimuli (e.g a flashing light) and our current goals (e.g watching the footy). When bottom-up processing fails Top-down processing to the rescue! MOOOOOO! Summary : !Cognitive psychology concerns the study of mental processes such as those involved in perception, attention, memory, language and thinking.!

~ Perception topic ~

1) Object Recognition Perception: ● Refers to our ability to extract meaning from sensory input ● It includes audition, taste, touch and olfaction (smell), but research is dominated by vision. ● Vision alone accounts for over 50% of all neurons in our cortex. ● Perception is a constructive process. ● Brain receives sensory input allowing us to perceive an object. The Visual System (a misleading oversimplification)

2 Processing Streams - Ventral / Dorsal We have two visual pathways : ventral (what pathway) and dorsal ( where pathway)

The Visual System: A misleading impression of simplicity Studies like this (Tootell et al, 1982) support the notion that a near perfect representation of the external world is “projected” onto our primary visual cortex. The stimuli were displayed for 25-30 minutes and the monkeys were not conscious during the experiment… Object Recognition: A Three Stage Model

Gestalt Principles

● The whole visual percept is more than the sum of its parts. ● Our perceptual system constantly tries to impose organisation on its input. ● Components of an image are grouped together on the basis of certain visual properties. ● Laws of “good continuation” and “closure” give rise to “illusory contours”

Examples of illusory contours : Top down influence has a massive influence in constructing your vision.

Bi-stable stimuli: e.g vase or two faces?

Shape Perception ❖ Primarily “bottom up” processes produce a “primal sketch” (Marrm 1982) ❖ This sketch contains “primitives” edges/orientations/positions/lengths/colours etc. ❖ “Top down” processes (such as Gestalt laws) are used to group collections of primitives together into “lines, curves, larger blobs, groups and small patches” - symbolic primitives. Object Recognition : 3 MODELS 1. Template matching (prototype theory) 2. Feature analysis 3. Recognition by components ( structural theory)

1. ● ● ● ●

Template matching (prototype theory) A template is an internal representation A memory against which the visual input is matched. Computer based object recognition programmes use templates. Intuitively plausible - object recognition must involve some kind of contact with a “comparable internal form” ● But what rules determine whether a match is made? ● How many different templates are needed.

2. Feature analysis - Assumes lower level features are analysed first ● The perceptual system searches for simple but characteristic features of an object ● Supported by neurological evidence (e.g. Orientation selective cells in visual cortex) ● Most research focuses on letter / word recognition (used to read postcodes!) ● Letter A made up o f/\and – ● But what about V and X? Both made of / and \ ... Spatial relationship important ● What about complex natural objects? 3. Recognition By Components ( Feature analysis in 3d) ● Any specific view of an object can be represented as an arrangement of simple 3D shapes – geons (Biederman, 1987) ● Geons are “viewpoint invariant” – easily “recoverable” from a 2D retinal image ● “Invariant properties” include cotermination & parallelism ● Object recognition is impaired when geons are made “nonrecoverable” by removing termination points BUT ...Geons reappear with “splats”: - Not easily explained by ‘recognition by components - Colour can aid recognition too.

Summary: ● Object recognition is rapid and apparently effortless ● It is a constructive process, not a passive one ● It combines “bottom up” processes (e.g. edge detection) with top down processes (e.g. expectations / memory)

● models of object recognition are not necessarily mutually exclusive, and object recognition may well involve elements of template matching / feature analysis / recognition by components

Face recognition (lecture 2) Theoretical models of face processing: The Bruce and Young (1986) model of face recognition:

1.Construct representations of the face. 1.Different representations are used for different purposes (age, gender, expression, identity perception, lip-reading) and differ for familiar and unfamiliar faces. 1.For recognition, a familiar face activates a “Face Recognition Unit” – sense of familiarity. 1.FRUs are linked to “Person Identity Nodes”, gateways to semantic information about the person. 1.PINs are linked to name generation.

Evidence for the Bruce and Young model: 1.Diary studies of recognition failure: (Young, Hay and Ellis 1985) Support the sequential nature of the recognition process. 2. Laboratory studies of face recognition: RT data support model – familiarity decisions are faster than retrieving semantic information, which is faster than naming.

3. Neuropsychological data: Support claim that identity, emotion perception, etc. are largely separate processes (although the model overstates their independence). Limitations of the model: Descriptive – vague on how these processes are actually carried out. Delusional misidentification syndromes: Capgras - a familiar person has been replaced by an imposter. Frégoli - unfamiliar people are a familiar person in disguise. Partial damage here: associative prosopagnosia with covert recognition

Damage here: Capgras

Excessive PIN activation: Frégoli

Interactive Activation and Competition (IAC) model Burton, Bruce and Johnson 1990

FRU’s = face recognition units SIU’s= Semantic information units NIU’s = Name identification/ information units PIN’s= Personality identity nodes. *What this model does over and above the Brice and Young model is that it nicely explains priming effects. IAC model- repetition priming : seeing a face repeatedly speeds up the facial processing of that face. If you saw a face of Paul McCartney once...you will be quicker to respond to any picture of him the second time. Quicker than a photo of John Lennon.

IAC model - semantic priming : weaker than repetition priming, more fragile

Evidence for the IAC model: 1. Laboratory studies of face recognition: RT data support model – explains priming effects well (including cross-modal priming). 2. Neuropsychological data: Can account for different types of face recognition deficit (prosopagnosia) in terms of damage to FRUs or PINs, or their disconnection. Limitations of the model: The Bruce and Young and IAC models both gloss over how faces are recognised in the first place. THE NATURE OF FACE Representations How to find out what information is used for face recognition: Define conditions under which performance is disrupted or preserved. 1. Face recognition is orientation-dependent. 2.Face recognition is contrast-dependent. 3. All forms of face processing (identity, emotion, age, gender) involve some kind of integrative “configural” processing. Demonstrations of face processing’s sensitivity to orientation: The Inversion Effect: upside-down faces are hard to recognise (Yin 1970). The Thatcher Illusion: subtle relational changes are not apparent in inverted faces (Thompson 1980).

Configural processing definitions (Maurer et al 2002): The terms “configural” and “holistic” have been used to refer to different things. 1. First order relational processing: Basic “face plan” of two eyes above nose above mouth. Examples of 1. First order relational processing: -

Basic “face plan” of two eyes above a nose above mouth.

2. Holistic processing: Relational processing that binds together the whole face. Examples of 2. Holistic processing: “Mask of love” illusion (Sarcone 2011) 3. Second order relational processing: Fine-grain spatial interrelationship between “features”. e.g. Richler (2009): “…subtle differences in spatial relations between face features being encoded…” Tanaka and Gordon (2011): “…encoding of metric distances between features”. The composite Face Effect ( Young, Hellawell and Hay 1987) - Upright faces evoke obligatory holistic processing. - Inversion abolishes this effect. - Not confined to recognition e.g. emotion (Calder et al, 1999) and age (Hole and George, 2011). Two routes recognition Collishaw and Hole (2000): can recognise faces if either featural or configural information are present, but not if both are removed (e.g. inverted blurred faces are unrecognisable). Problems with “fine-grain configural processing” accounts: 1. Cannot reliably match different views of the same face, even under ideal conditions. 2. Cannot account for non-effects of stretching, shearing and other distortions.

3. Does not explain why negation affects recognition so badly. Burton et al (2015) : Distance between outer edges of irises is expressed as a multiple of standardised iris diameter (a-b). Large within-person variation: eye-separation is not an individuating metric.

Kleinberh, Vanezis and Burton (2007) : Photoanthropometry anthropometry is an unreliable technique for matching images.

Jenkins et al (2011): difference between familiar and unfamiliar face-matching : There is only 2 different guys on these photos

Hole, George, Eaves and Rasek (2002): Face recognition is unaffected by global linear affine transformations other than inversion (stretching, squashing, shearing) Effects of contrast inversion (“negation”) Negative faces are very difficult to recognise, even though they are processed configurally (Hole, George and Dunsmore 1999).

Where in the brain is face processing carried out? Face recognition involves an extensively distributed processing network. Haxby, Hoffman and Gobbini (2000):Core system (face processing) and Extended system (retrieving non-visual information about a face). FFA- fusiform gyrus- fusiform face area-recognising faces as faces- connected with frontal area of temporal lobe-memory

Barbeau, Taylor, Regis, Marquis, Chauvel and Liegeois-Chauvel (2008):

Intracranial ERP study of time-course of famous face recognition. Massively distributed processing from 110 -600 msec post-stimulus - at least seven structures involved. Processing is not "one-way" - frontal areas influence "earlier" stages. FG - invariant aspects of faces; STS - changeable aspects. Perirhinal cortex -signals "familiarity". Temporal structures - recognition. Dark blue= periods when recognition effects were found. Conclusions: - Models are useful for ordering the data that we have, and for making predictions. - The Bruce and Young model has been extremely useful as a basic description of face processing. - Despite a huge amount of research, it remains unclear exactly how face recognition is achieved – some kind of “configural” processing occurs automatically with upright faces, but recognition cannot be achieved via fine-grained configural processing as is often claimed. - Familiar and unfamiliar face recognition show similarities and differences: familiar face recognition involves “abstract”, robust representations whereas unfamiliar face recognition is based on “pictorial”, episodic representations. - Lots of different brain regions are involved in face processing!

3)Agnosia/ Prosopagnosia Agnosia (when object recognition fails): typically occurs after damage to the occipital or inferior temporal cortex. -

Different types of agnosia reveal important cues concerning the processes underlying object recognition.

“The impairment of visual object recognition in people who possess sufficiently preserved visual fields, acuity and other elementary forms of visual ability to enable object recognition, and in whom the object recognition impairment cannot be attributed to... Loss of knowledge about objects.” Farah (1999), APPERCEPTIVE AGNOSIA Def: object recognition is impaired, because deficit in perceptual processing. -

Able to move and negotiate obstacles without difficulty Their grasp reveals knowledge of size and shape ( Goodale & Milner, 2004) Low-level binding of feature appears to be absent Unable to perform basic copying tasks

Where in this model would damage result in apperceptive agnosia occur?

Damage to this stage

ASSOCIATIVE AGNOSIA : LH Def: perceptual processes are essentially intact, but there are difficulties in accessing relevant knowledge about objects from long-term memory. -

Copying and matching tasks are unimpaired Patient unable to name the object despite intact knowledge Involves a failure in accessing knowledge about the objects

Where in this model would damage resulting in Associative agnosia occur?

intact? Damage to this stage

But...apperceptive vs. associative is an oversimplification - there are many other “types” of agnosia. PROSOPAGNOSIA -

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Profound loss in ability to recognise faces usually due to a right inferotemporal lesion. Though unable to recognise previously familiar faces via visual input, recognition by other modalities remains intact. Thus, individuals can be identified by for example their voices. Note that the ability to recognise faces is tested through overt behavioural measures. But do prosopagnosics not recognise faces in any manner?

COVERT recognition (unconscious recognition) ● Peak skin conductance responses (SCRs) occur 1-5 seconds after a face has been presented ( red arrows) ● Peak amplitudes are larger for a familiar relative to an unfamiliar face (Tranel et al., 1985). ● Similar patterns have been observed for prosopagnosic patients ( Ellis et al., 1993)

Recognition without feeling: Capgras delusion ★ Patients with Capgras delusion recognise a face and yet deny the identity of the individual. ★ For instance, Alan Davies, after a car crash insisted that his wife died in the crash and the woman living with him was an imposter!

Prosopagnosia vs. Capgras Syndrome: two routes to recognition. ★ Yellow route is the covert dorsal route through the superior temporal sulcus and inferior parietal lobe. ★ Red is the overt ventral route ★ Loss in the ventral stream can results in prosopagnosia ★ Loss in the dorsal stream can result in Capgras delusion. SUMMARY : ● ● ●

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Visual agnosia is a deficit of visual object recognition Typically results from damage to the occipital or inferior temporal cortex (early in the ventral stream) Lissaur (1890) first distinguished different types of agnosia: o Apperceptive: Low-level binding of features is compromised o Associative: Access to associated knowledge is compromised This dissociation is supportive of modularity in the process of visual object recognition Modularity is central to the cognitive neuropsychology approach and while useful is typically an over simplification.

4) Synaesthesia -

For some people letters and numbers have their own particular colours; sequences glide through space etc.

Perception is a Brain Process •Eyes, ears, nose, mouth and skin have receptors that convert physical signals to neural signals •The brain perceives the world based on information from each sense, AND from information from different senses AND from stored knowledge of the world •Physical world not the same as the perceived world (e.g. visual and auditory illusions) Multi-Sensory Perception

= the process by which information from different senses is brought together Advantages: ★ More efficient than processing each sense separately ★ Enables us to establish a single coherent perspective of the world ★ Enables us to act on the world.

Colour influences taste :

Sound influences taste : eg. carrot Vision influences sound:

The McGurk Illusion ❏ ❏ ❏ ➢

“BA”: is presented to ears “GA” is presented to eyes > Subject perceives “DA” fMRI shows that silently looking at moving lips activates the auditory part of t...