Studies Flashcards
Damasio et al (1994)
- PHINEAS GAGE a construction worker was laying new rail track
- a power ful explosion sent the tamping iron through his face, skull and brain and then into the sky
- he survived but changes happened to his character and behavior
- after the incident he had no impairment of movement or speech and new learning was intact
- memory and intelligence appeared unaffected
- became disrespectful and impulsive and less responsible
-died 12 years later due to epilepsy related to incident
Aims of the study (Damasio et al.)
Aims
-build model of skull to map out how iron rod passed through head
-using data able to create 3D computer representation of the skull
-able to identify which part of brain were most likely to have been damaged
-he wanted to discover if areas had been damaged around
-assumed it was mostly damaged in frontal lobe
- he wanted to discover if any other areas had also been damaged
Results (daniasio et al) (1994)
- only damage occurred in the frontal lobes (both left and right hemisphere)
-iron bar passed through left eye socket meaning that there was likely to be more damage to the undelying white matter (brain and spinal cord tissues, consisting mainly of nerve fibres) in the left hemisphere, frontal lobe
-this means gage was unable to pass neural messages in this part of the brain making it useless
Conclusions (damasio et al ) (1994)
-compared areas of his brain most likely to have been damaged with the reported changes in his personality after the accident
-ventromedial area of the frontal lobe seems to be important for making sensible decisions and controlling our Impulses around people
Sperry (1968) backround
- Reports a number of patients whosuffer from server epilepsy led them to experiencing frequent seizures
- underwent surgery that involved severing corpus collosum(seperating the hemispheres)
- surgery appeared to he successfull experiencing no further seizures or some (two) suffering less frequenty
- some problems with short term memory and concentration span
- split brain patients
Sperry (aims)
- to find out the cognitive functions that are linked to each hemisphere
- aimed to assess the behavioral neurological and psychological effects of the split-brain surgery
-how split brain worked compared to a normal brain
Sperry (procedure)
- Reports on 11 patients who underwent surgery for epilepsy
- ( task 1) - asked patients to fix their eye gaze on a particular spot and then protected words or pictures for 1/10 th of a second
- could be sure that the information only entered eitherthe left or right hemisphere
-Then had to feel for a particular object behind a screen to identify what they had apparently seen with their eyes - ( task 2) asked patients to pick an item from a bag and name the object (without seeing it)
- (task 3) - showed a picture of a wall clock to the patients right hemisphere and asked them to pick the object closest to what they had seen with their left hand
- ( task 4) A sum was shown to the right hemisphere and patients were asked to use their left hand pointto what they thought was the correct answer to the sum
-( task 5) A picture of a nude was presented to the right hemisphere to see what the reaction would be - (task 6)patients performed block designntests - a type of spatial task
Sperry(1968 ) results
- (task 1) - patients could say ‘case’ (right) and write it but reportednut seeing anything to the left side
- if asked to select they saw to the left with their left hand, they could choose key correctly from either the items behind them on from on array of images indicating that the left visual field was being processed by the right hemisphere and the left hand by the right hand Luis versa)
- (task2) - if patients used their right hand they could name the object
If they used their left hand they were unable to name it, but able to retrieve it from a grab bag - (task3) - they were able to pick a wristband with their left hand
- another test they connected a a’ peace of silver were with a fork
- showed the limited language ability in the right hemisphere
- (task 4) - left hand could point to correct answer
- right hemisphere involved in basic calculations
- (task 5) - picture of made would produce blushing or giggling(no verbal response to image)
- right hemisphere was involved in emotional processing
- (task 6) - right hemisphere was judged to be superior to left hemisphere in tasks involving drawing, spatial awareness I relationship and performing block designs tests
Sperry (conclusion)
- left hemisphere was primary hemisphere for the processing in language
- right was able to road words make mental associations, process emotional reactions and solve simple arithmetic
Issues and debates
Understanding how psychology is changed over time
- Damasio et al (1994) Phineas gage
- areas of the brain ( brain damage )
- technology ( EEG - a way to measure brain wave activity in living brain - start of ways to studythe brain that didn’t rely on the patient being dead or
Procedure of the study (Damasio et al.)
-began taking photos and measurements of skulll
-build 3D replica model
-took measurements of rod (3cm diameter and 109cm long)
-matched Jo possible entry and exit points for iron rod on their model
-20 diff entry points & 16 diff exit points were tested
-once found 5 most likely paths he used virtual replica to map out which areas would have been damaged
Strength of danasio et al
Able to use modern day technology
Use of computer model meant evidence could be seen rather than inferred from information gathered after accident
Can now make predictions about what changes to behaviour we can expect if someone damages their frontal lobe
Weakness of the study
Information on how the accident happened is based on reports gathered over 150 years ago (not very accurate)
Problem with generalising the information about this case study as brain damage was unique to gage, unlikely someone else will have exact damage so information might not be useful to understand what happens when damaging frontal lobe
