C2: Biological Psychology Flashcards
Sperry: aim
To investigate the effects of hemisphere deconnection and to further understand the functions of the left and right hemispheres
Sperry: method
Quasi experiment, or a series of case studies
Sperry: independent variable
Presence of absence of a split brain
Sperry: dependent variable
Whether the participant could name objects, recognise objects and draw objects
Sperry: participants
Split brain participants were 11 patients (male and female) who had already had the split brain operation to disconnect the two hemispheres. All of these have a severe history of sever epilepsy which had not responded to drug therapy
Sperry: visual test procedure
- Show one or both visual field a stimulus
- When presented to one eye, the other stays covered and to focus on a fixation point, information flashed fro 1/10th of a second
- Similarly when image is presented to both visual fields, focus on a fixation point and image is flashed for 1/10th of a second
Sperry: tactile test procedure
- Participants could not see their hands or the objects that they had been given to hold
Sperry: visual tactile test
- Both sight and touch
- Image presented to left or right visual field and participant would have to try and find the object from an array using their left or right hand
Sperry: test of the right hemisphere procedure
- Array of geometric shapes are presented to both visual fields
- In the middle, a nude picture flashes to the left visual field only, so seen by the right hemisphere
- Participant is later asked fi they had seen anything other than geometric shapes
Sperry: conclusion
Concluded in most patients the dominant hemisphere is the left hemisphere due to language skills which are based in the left hemisphere controlling words and ability to speak. He also concluded a severing of the corpus callosum stops the two hemispheres from communicating with one another
Casey: aim
To build on previous research to assess whether delay of gratification in childhood predicts impulse and self-control abilities at the behavioural and neural level in adulthood
Casey: research method
Quasi experiment, longitudinal
Casey: independent variable
Whether the participant was a high or low delayer
Casey: dependent variable for experiment 1
Was the participants performance on the impulse control task in terms of reaction times and accuracy.
Casey: dependent variable for experiment 2
Same as experiment 1, but researchers also examined the brain scan results from the fMRI
Casey: experimental design
Independent and repeated measured
Casey: participants
562 children aged 4 years old took part,
1993 aged 20= 155 of the original sample completed self-report measures of self control
2003 aged 30= 135 of original participants
2011 aged 40= 117 of 135
Casey: umber of high and low delayers in 2011
High delayers- 60
Low delayers- 57
Casey: experiment one number of high and low delayers
High delayers- 32 (12 male, 20 female)
Low delayers- 27 (11 male, 16 female)
Casey: experiment two number of high and low delayers
High delayers- 15 (5 males, 10 females)
Low delayers - 11 (7 male, 4 female)
Casey: experiment one procedure
- Participants sent laptops to home using Inquisit Software to present experimental tasks
- Participants were required to complete two types of go/no go tasks
- Reaction times measured as well as accuracy
- Two versions of this are the hot and cold condition
- Before each run, a screen appeared on the laptop indicating which stimulus category served as a target, asked to respond quickly
- Each face appeared for 500ms followed by a 1 second interval, total of 160 trials
Casey: experiment one reaction time results
There were no effects of delay group on reaction time measures to correct ‘go’ trials. This means that it didn’t matter if you were a high or low delayer when correctly pressing the button during the ‘go’ trials