PSYC 415 -- Some General Effects of Brain Damage

Frontal Lobe Lesions - exact character depends on location of lesion
1) disturbances of motor function and movement programming
2) disturbances of voluntary gaze (patients don't "look at the right places" to
   answer questions)
3) speech production (Broca's area and supplementary speech area)
4) disturbance in intelligence
   a) but not in IQ test taking ability - convergent thinking (just one answer)
   b) divergent thinking impaired - ability to come up with multiple answers
5) loss of behavioral spontaneity
6) impaired strategy formation - esp. in novel situations
7) impaired response inhibition, perseveration
8) failure to comply with instructions, rule breaking, risk taking, failure to
   learn from experience
9) impaired autobiographical memory - e.g., patients can remember going to HS,
   they can tell what HS was like, but they can't relate personal stories
   about HS
10) impaired social and sexual behavior - personality changes
    a) pseudodepression - apathy, indifference, loss of initiative, reduced
       sexual interest, reduced verbal output (more common w/left hemis. damage)
    b) pseudopsychopathy - immature behavior, lack of tact and restraint,
       profanity, promiscuity, lack of social grace (right hemis. damage)

Temporal Lobe Lesions
1) disturbances in auditory perception
   a) difficulty discriminating speech sounds and "tone of voice" (prosody)
   b) difficulty with music perception
   c) auditory hallucinations - due to spontaneous activity in auditory cx.
2) Wernicke's aphasia - inability to produce or comprehend meaningful speech
3) disturbances in visual perception - visual agnosia, prosopagnosia
4) memory - anterograde amnesia (due to hippocampal damage)
5) affective changes - perhaps due to involvement of amygdala and limbic cx.
6) temporal lobe personality (very few patients display all of this syndrome)
   a) pedantic speech and egocentricity
   b) "stickiness" - person persists in discussing personal problems, and you
      "get stuck listening to him"
   c) paranoia
   d) obsessive preoccupation with religion
   e) proneness to aggressive outbursts

Occipital Lobe Lesions
1) blindness for part or all of the visual field - cortical blindness
2) visual agnosia - failure of object recognition
3) visuospatial agnosia - topographical disorientation
4) prosopagnosia - facial agnosia (including for their own faces)
5) alexia - inability to read (left hemis. damage)
6) failure of visual imagery (imagination)

Parietal Lobe Lesions
1) somatoperceptual disorders - e.g., astereognosia (inability to recognize
   objects by touch), asomatognosia (loss of body sense and condition)
2) contralateral neglect (esp. after right hemis. damage)
3) optic ataxia - failure of visually guided movements
4) apraxia - a peculiar loss of skilled movements (to be discussed in detail)
5) failure of spatial cognition - e.g., mental rotation
6) impaired IQ testing ability - failure of convergent thinking