Psyc20006 Biological Psychology (Melbourne Uni) Lecture 9-10

Front 1

Localisation of EEG signal

Back 1

can be done by extrapolating btwn the electrodes to display how the amplitude of the signal varies across the scalp

Front 2

Dipole fitting, attempts to deduce:

Back 2

- the neuronal sources that give rise to distribution of electrical potential recorded on the scalp. - assumes that these sources can be thought of as dipoles the project (+) and (-) electric fields in opposite directions. - orientation, location & # of dipoles determine the electrical field recorded @ the scalp. - (appropriateness of technique still debatable)

Front 3

Study: Schafer & Marcus 1973

Back 3

- evidence that N100 wave form disappears if subject generates the stimulus. - indicates that wave form is linked to novelty.

Front 4

Study: Schafer & Marcus 1973
SUMMARY

Back 4

- if observer attends to the left side of space, the N2 component is larger over the right visual cortex (vica versa)- used to determines where observer is attending

Front 5

N2pc

Back 5

- recording two channels 01G and 02G. On each channel we can measure an ERG. if subject is attending 2L- then N2 component will be greater on the 02G then the 01G (opposite sides)

Front 6

Study: Carlsie & Woodman 2011

Back 6

- in visual search one often looks for a predetermined target. Therefore, one is searching for an item which is stored in memory.

Front 7

Study: Carlsie & Woodman 2011. 2 CONTRADICTORY Theories OF ATTENTION..

Back 7

1.theory of biased competition. 2. the novel theory of visual attention. (the study used EEG to test these theories)

Front 8

Event related potentials: EEG signal caused by the presentation of a ................ -

Back 8

stimulus,

Front 9

N1 (or N100)

Back 9

a large, negative-going evoked potential measured by electroencephalography

Front 10

Serial search:
Parallel search:

Back 10

- target is similar to distractors thus observer has to attend to each item until they locate target.
- all items are attended to simultaneously