Exam 3 Studies Flashcards
Gazzaniga study
Self recognition in a split brain patient JW
2-3 things we know in the Gazzaniga study
- Face recognition of others typically relies on structures in the right hemisphere
Gap in our knowledge in the Gazzaniga study
What hemisphere is self-recogntion localized in?
Independent variable in Gazzaniga study
% MG or % JW
Dependent variable in Gazzaniga study
Proportion of yes in left hemisphere or right hemisphere
Method of Gazzaniga study
A split brain patient was shown a gradient of morphed faces (10% his face, 90% a familiar other; 50% his face, 50% familiar other etc)
Results of Gazzaniga study
The right hemisphere is better at recognizing the familiar other at lower percentages, while the left hemisphere is better at recognizing the self at lower percent
Conclusion of Gazzaniga study
A double dissociation between the right and left hemisphere in self and other recognition occurs.
Liu study
Optogenetic stimulation of a hippocampal engram
activates fear memory recall
2-3 things known in the Liu study
- A specific memory is thought to be encoded by a sparse population of neurons
- The dentate gyrus plays a critical role in discriminating between similar contexts
Gap in our knowledge in the Liu study
Whether it’s possible to elicit the behavioral output of a specific memory by activating a memory engram/memory trace
Independent variable in the Liu study
Whether a blue light was shined/optogenetic manipulation occurred
Dependent variable in the Liu study
Behavioral: freezing behavior of the rat
Neural: resulting fluorescence of rat’s brain to show activity
Method for the Liu study
- Mice were exposed to a non-dangerous environment, then a very different context where they developed fear responses
- Mice were put on special diet so neurons in dentate gyrus would produce channelrhodopsin when active, which is sensitive to blue light
- Mice were put in the non-dangerous environment then had a blue light shone on their dentate gyrus.
Results of Liu study
When optogenetics activated neurons involved in the fear response in a non-fear conditioned environment, rats exhibited fear responses such as freezing
Conclusion of the Liu study
Activation of the subset of dentate gyrus neurons involved in the fear conditioning led to behavioral reproduction of that fear behavior, creating an artificial memory
Bagherzadeh study
Alpha synchrony and the neurofeedback control of spatial attention
2-3 things known in Bagherzadeh study
- Increases in alpha synchrony are associated with decrease in neuronal excitability
- Correlation between covert attention and lateralized parietal alpha oscillations has been established in MEG studies
- Increased alpha synchrony in one hemisphere is associated with reduced attention in the contralateral visual field
Gap in our knowledge in Bagherzadeh study
Whether alpha synchrony has a role in attention towards attended targets vs. distractors
Hypothesis of Bagherzadeh study
Neurofeedback to modulate alpha synchrony in one hemisphere will alter visual processing and attention in opposite hemifield
Independent variable in Bagherzadeh study
Modification of alpha synchrony in right or left parietal cortex
Method of Bagherzadeh study
Subjects modulated their alpha asymmetry to alter contrast of stimuli used in a match to sample task presented at the center of gaze
Dependent variable of Bagherzadeh study
Performance on Posner cuing task
Results of Bagherzadeh study
The change in alpha synchrony causes a bias in visual processing and attention in the corresponding visual field
