Stroop Task

2. Stroop Task

4. Wisconsin Card Sorting Task

5. Following a rule • Attention • Error based learning

7. PFC DLPFC inputs: • primary sensory, mostly dorsal stream. VLPFC inputs: • Multimodal inputs from the STS. • Some ventral stream inputs. OFC inputs: • VTA • Amygdala, hippocampus & thalamus Heavy input from VTA carrying dopamine signal. Many interareal connections. DLPFC projects to: • Supplemental Motor Area (SMA) • Cingulate • Primary Motor Area (M1) • Cerebellum • SC • FEF

8. SEF Dorsomedial frontal lobe Highly connected to FEF and very similar. • Projects to the caudate, SC and brainstem just like FEF. • Fewer intracortical connections then FEF. Mainly LIP and MST. Mainly dorsal stream input, not much ventral Far more connected with Cingulate then FEF Low level stimulation evokes saccades and neurons have saccade related activity Visual cells: • Slower • Less consistent Delay cells: • Fewer • Slower • More multimodal Delay saccade: • Slower • Less accurate Presaccadic: • Same Postsaccadic: • Earlier Stimulation generates a single saccade not a series SEF has eye position dependant activity SEF alone cannot generate saccades

9. SEF SEF FEF

10. Anterior Cingulate Cortex (ACC) Very heterogeneous area including gross morphology and cytoarchitecture Dense connections with motor cortex and DLPFC • Implies a integration of cognition and action • Allows DLPFC to influence motor output Inputs from thalamus, VTA & indirect input from amygdala ACC has dense reciprocal connectivity with SEF Lesions: • Inability to initiate movement • Suppress externally triggered motor subroutines. Single unit activity: • Error • Rewards • Action Initiation • Combinations FMRI activity: • Monetary gains/losses • Emotional decision • Conflict Stimulation: • Causes movement (eyes) • Monkey calls.

11. Anterior Cingulate Cortex (ACC)

12. Early PET study found major activation of ACC during Stroop task. Any task in which there was allot of cognitive “conflict” or increasing task difficulty Most ACC activation was accompanied by PFC activation Two theories emerged: Conflict detection and Error detection

13. Conflict theory Starts from a an idea about how the brain works: Control theory That there are conflicting streams of information in the brain that must be managed or controlled. Thus, you need some module to monitor conflict so it can be managed. ACC is active during high conflict tasks like the stroop test and go/no-go tasks. ACC is also active when errors are made: well this is a conflict between the correct and incorrect response.

14. Error theory Starts from an physiological observation: The error-related negativity (ERN) The ERN is an event related potential (ERP) which is an average of electroencephalogram or EEG aligned to some event. With the onset of an erroneous choice or the revelation of an erroneous choice there is a larger negativity in the EEG that is generated by the ACC. They also have a host of imaging studies showing that the ACC singles errors.

15. Schall’s Countermanding task Test subjects ability to control a movements initiation by periodically presenting a stop signal during reaction time task.

16. Schall’s Countermanding task Probability that you wont cancel increases with stop signal delay. Short latency saccades are less likely to be canceled because the stop single does not have time to influence the system. Competition between a GO and a STOP signal. The stop-signal reaction time (SSRT) is the time required to cancel a sccade

17. Schall’s Countermanding task Movement cells began to build to threshold but on canceled trials collapsed. Fixation cells are active after fixation and pause during the saccade. Decrease until the stop signal and then begin to rise on canceled trials.