Biopsych+neuropsych

frontal lobe

Largest lobe of the brain

3 areas: Prefrontal cortex, motor cortex, broca’s area

prefrontal cortex areas

Dorsolateral PFC

Medial PFC

Orbitofrontal PFC

Motor cortex

Primary motor cortex

Premotor cortex

Supplementary mc

Frontal eye fields

Broca’s area

DLPFC (dorsolateral PFC)

Functions:

Working memory

A place where past and future meets: looks backward in time to create memories from sensory input and looks forward in time to assemble a motor plan of action.

Lesion: executive function deficit

Orbitofrontal PFC

Emotional processing

Recieves info from amygadala

Emotional perspective taking

Reward contigencies

medial OFC

Anticipation of rewards

Addiction

Lateral OFC

Absences od rewards

Aversion

Medial PFC

The social brain

Long term memory

Emotional processing thru limbic system

Premotor cortex major areas

Dorsal (PMd )

Ventral (PMv)

Inferior frontal gyrus (broca’s area)

Dorsal PMd

Active for choosing movement from its mov lexicon

Ventral (PMv)

Contains mirror neurons that recognise others movment and select similar or different actions.

Fronal eye fields

Stimulus directed eye movmnt

Voluntary control of conjugate (horizontal) eye mov

Saccadic eye movmnt

Lesion to frontal eye fields

Turns eye to opp side

Lose of conjugate eye movmnt

Broca’s area location

Left hemisphere FL

Note: Dominant hemisphere —> speech

non-dominant —> emo component of speech

Motor humunculus

Wilder penfield

Cartoons of body parts to represent the areas of primary motor cortex and pre motor cortex.

Disproportion in the relative sizes of body parts.

Major cortical tracts and motor pathway

Cortico-spinal tract

Corticobulbar tract

Ventro-medial tract

Rubro-spinal tract

Corticospinal tract

2 functionally distinct tract

Lateral tract: distal muscles (forearm, lower limb, hand & finger).

Ventral tract: medial muscles ( trunk, upper limbs…)

Damage to lateral corticospinal tract

Comprimise skilled movments

Damage to ventrak corticospibal tract

Affect posture and ambulation

Cortico-bulbar pathway

Axon descend till pons, where they innervate some ofnthe cranial nerves to control facial, mouth and tongue muscles.

Projection to upper part of the face tend to bi-lateral, where lower face and mouth region tend to be contralateral.

Rubro-spinal pathway

Function: movment of limbs independent of movment of trunk

Supplementary motor area

Buffer store cos its position (in a heirarchy) to cordinate motor plans been ‘approved’ by the big execution via the pyramidal neurons of primary motor strips.

“Bereitshaftpotentials”

Temporal organisation of bhvr

Function of FL

Pfc selection depends on:

1. Internal cues

2. External cues

3. Context cues

4. Autonoetic awareness

Autonoetic awareness

Tulving

Bhvr is affected by lifetime experiences and goals.

Impairment in AW: Deficits in the self-regulation of bhvr. Seen in DID, PD, SCHIZO, delusional d, ASD

Dorsal visual stream

Object recognition (where pathway)

DLPFC

Dorsal DLPFC - monitoring info in WM

Ventral DLPFC - Regulate the encoding & retrieval of info

Medial PFC

Initiation of activity

Socio-emotional-motivation aspect of bhvr

MPFC

Ventral medial PFC (VMPFC)

Dorsolateral PFC (DMPFC)

Ventral medial PFC

Somatic markers

Processing of risk and fear

Dorsomedial PFC (DMPFC)

Regulating & inhibiting emotion.

Introspection

Sense of self

Motivation and initiation of activity

Decision making on the basis of morality

Ventral visual stream

Spatial behavior (what pathway)

Symtoms of frontal lobe lesions

Disturbances in motor functions:

1. Loss of fine movemnts

2. Movmnt programming

3. Voluntary gaze

4. corollary discharge

5. speech

Loss of divergent thinking

1. Bhvr spontaneity

2. Strategy formation

3. Frequency estimate

Environmental control bhvr

1. poor response inhibition

2. impaired associative learning

3. risk taking & rule breaking

4. Gambling

5. self regulating bhvr difficulty

Poor temporal memory

1. Working mem

2. Delayed response

Personality changes

1. Social bhvr

2. Sexual bhvr

Removal of supplementary motor cortex

Disruption of nearly all voluntary movements

Right & left FL damage (Kolh and Miller study)

Difficulty in copying series of facial movments

Voluntary gaze

Function of frontal eye field

Incase of damage: alteration in voluntary gaze

Corollary discharge ( secondary messages)

A neural signal must produce both the movement and a signal that the movemnt is going to take plade.

When you voluntarily move your eyes, u generate a neural signal that movmnt will happen.

Risk taking & rule breaking

FL damage: failure to comply with instructions.

Role of OFC in risk taking

In gambling: FL lesion pt didnt find ambigous task aversive but controls did.

Tests FL lesions

Response inhibition : WCST, stroop test

Verbal fluency: Thurstone word fluency

Non verbal fluency: design fluency

Working memory : set order

Planning: TOL

Assymmetry of FL function

Left FL : language

Right FL: non verbal mov (eg. Facial expression)

Memory

1. Encoding: left PFC

2. Retrievel: Right PFC

Functions of Premotor cortex

Ventral & lateral: movmnt based on external cues

Medial region:

1. respond to internal signals from brain area.

2. Relay centr for executing specific physical actions

3. Contribute to learning, imitation amf support

4. Social cog skills (eg. Empathy)

Right PMC: spatial activities

Left PMC: tasks that r not spatial in nature.

PMv

PMd

Frontal eye fields

3 main regions of Temporal lobe

Superior TG

Middle TG

Inferior TG

Insular cortex

Primary gustatory cortex

Auditory association cortex

What pathway ( hierarchical sensory pathway)

Stimulus recognition (WHAT IS THATTTT???)

Dorsal pathway ( where pathway)

Spatial location (WHERE IS ITTT)

Polymodal pathway

Stimulus categorisation

Medial temporal projection

long term memory

3 sensory functions and 4 main functions of TL

3 main function:

1. Processjng auditory input

2. Visual objecy recognition

3. Long term storage of sensory inp

   4 main functions:

   1. Obj recog

   2. Categorisation

   3. Directed attention

   4. Cross modal matching

   5. Recalling from LTM

Cross modal matching

Cortex of Superior temporal sulcus

Affective response function of

Amygdala

Spatial navigation function of

Hippocampus

Biological motion function of

Superior temporal gyrus.

STS: Involved in social meaning making of gestures.

social perception and social cognition

Two type of memort

Implicit

Explicit

Neural basis of implicit memory

Neocortex —> basal ganglia —> ventral thalamus —> premotor cortex

Neural basis of explicit memory

Entorhinal pathway (integrative forms of memory)

Parahippocampal cortex (visuospatial memory)

Perirhinal cortex (visual object memory)

Types of amnesias

Reterograde

Anterograde

Transient global amnesia

Infantile drug induced

Fugue state

Korsakoff’s syndrome/wernicke-korsakoff sundrome

Alzhiemers

Dissociative amnesia

Neuroanatomical vasus of amnesia

LESIONS IN

Cingulate gyrus (posterior part)

frontal and prefontal lobes

mammilo-thalamic tract (diff in recording of the stimulus, diff in immediate storage function)

Amygdala (memories emotional in nature)

Tests for amnesias

1. MSE

2. Galveston orientation & amnesia test (GOAT)

3. Weschler’s memory scale

4. Kingshill test or 6 CIT

5. General tests (learning a word list, learning pairs od words, passage test, corsi’s test “knock cube test”

Galveston Orientation and Amnesia Test (GOAT)

The Galveston Orientation and Amnesia Test (GOAT) is a clinical tool designed to evaluate post-traumatic amnesia (PTA) in patients with head injury. It helps determine when the patient regains orientation and consistent memory function after a traumatic brain injury (TBI).

Key Details:

Developed by: Levin, O’Donnell, and Grossman in 1979.

Purpose: To measure the duration and severity of post-traumatic amnesia (PTA).

Format:

Structured questionnaire with 10 items.

Assesses orientation to time, place, and person as well as memory for events both before and after injury.

Domains Assessed:

1. Orientation to person – e.g., name, age.

2. Orientation to time – date, month, year, time of day.

3. Orientation to place – city, hospital, ward.

4. Memory – events immediately before and after the injury, recall of hospitalization.

Interpretation of Scores:

100: No errors → fully oriented.

76–100: Normal or mild impairment.

66–75: Borderline.

<66: Impaired (still in PTA).

Corsi’s test ( “knock cube test” )

Measure visuospatical LTM

subject must learn sequence of 8 cubes, touched by examiner on corsi’s tablet and remember it after interval of 10 minutes.

Primary auditory cortex of right TL

Make pitch discrimination

“Musical store”

Right auditory association cortex

Amusia (tone defect)

Grant Allan, 1978

Types:

expressive : loss of ability to hum, sing, whistle a tone

perceptive: deficits in ability 6o appreciate various charac of music like pitch, harmony, melody.

Assymmetry of TL funtion

1. MEMORY

Left TL : verbal

Right TL : Non verbal

2. Processing of speech sounds: left TL

3. Processing aspects of musics: Right TL

4. Social & affective bhvr : TL function little known

5. Right TL lesion: imp in facial recognition & facial expression.