TMS and Perception Flashcards
who was the 1st scientific psychologist? What were 2 things he measured ?
Donders (1818-1889)
- mental chronometry: measuring how long a cognitive process takes
- Reaction - time experiment: measures interval between stimulus presentation and persons response
with what 2 tasks did Donders measure rxn time with?
- simple RT task: participant pushes a button quickly after a light appears
- Choice RT task: participant pushes one button if light is on right side and another if on left
what is Donders subtraction method?
choice RT- Simple RT = time to make a decision
How much longer for choice RT than simple RT ?
0.1 seconds
What are Donders 2 assumptions for the subtraction method?
- Assumption of serial stages: The stages of processing need to happen one after each other
- Assumption of pure insertion: Adding an additional stage does not change the length of the other stages
Mental processes/contents cannot be measured directly but can be inferred from a participants behaviour. Who is this?
Donders
Savings curve method for studying forgetting. Who?
Ebbinghaus (1850-1909)
what is Ebbinghaus saving method?
% savings = (initial reps - relearning reps)/ initial reps
–> the % fewer reps it took the second time doing the task (they remembered some)
% savings is most evident in the first __ days and then plateaus
6 days
who proposed computability
alan turing (1912-1954)
anything that can be computed is computable buy a simple ‘universal machine’ the turing machine
computability - alan turing
to the extent that what the in does compute, it can be specified as a computer program (represent what is going on in the mind on the computer)
computability - alan turing
“i date the moment of conception of cognitive science as 11 september, 1956, the second day of a symposium organized by a special interest group in information theory at the Massachusetts institute of technology”
george miller (2003) --> he introduced cognitive science
mental functions can be explained by the use of experiments following the scientific method
cognitivism
cognition consists of internal mental states whose manipulation can be described in terms algorithms
cognitivism
the scientific study of how people perceive, learn, remember and think about information
cognitive psychology
what does cognitive psychology reject as a primary tool
- what does it accept?
introspection
- accepts the existence of internal mental states
what was the 1st cognitive psychology test book?
Neisser’s Cognitive Psychology (1967)
who proposed phrenology
franz joseph gall (1758-1828) johann spurzheim (1776-1832)
what are the 4 characteristics of phrenology
- brain is the organ of the mind (before this they thought heart was)
- composite parts, with specific faculties
- area size indicates ‘strength’ of faculty
- size evident in skull (bumps, prominents, depressions)
- -> bump meant bigger there
in phrenology, they proposed there were ___ traits localized in distinct organs
- 19 common to humans and animals including ? (4)
- 8 uniquely human including ? (5)
- 27
- reproductive instinct, courage, sense of colour, sense of space
- wisdom, vanity, love of glory, satire, love of god and religion
phrenology is opposite from ? (2)
- anti-localizationists: argued brain regions are an indivisible unit
- anti materialists: argued mental/ spiritual faculties are not organic matter (not tied to the mind)
- -> the things are actually correct
how did Paul Broca contribute to localization in the brain
- speech loss not due to paralysis
- loss of memory of movements needed to pronounce words
where is Brocas area?
left frontal lobe
how did Carl Wernicke contribute to localization in the brain
-cases of lost of speech comprehension
where is wernickes area?
left temporal lobe
paul broca and wernicke studied using what method?
the lesion method
implications of Brocas and Wernickes discoveries (2)
- shift towards ‘ physiologically’ real functions (motoric and sensorial)
- localization of higher mental functions
3 characteristics of cognitive neuropsychology
- identifies the mechanisms that underlie cognition by studying the effects of brain damage (lesions)
- localizes these mechanisms to particular neural structures or processes
- identifies the functions of brain regions
timeline of non-invasive techniques to image the human brains
-ERP: 1935
-PET: 1975
-TMS: 1985
-fMRI: 1991
(exploded in the 80s and 90s)
the term cognitive neuroscience was coined by ______ and ________ in the back seat of a new york city taxi toward the end of the 1970
george miller and micheal gazzangia
2 basic goals of cognitive neuroscience
- determine how the brain mediates cognition and behaviour
2. relate neural structures to menta functions
what is fMRI measuring
blood oxygen levels in brain
what are ERPs measuring
electrical fields at the scalp
is fMRI invasive? is single unit recording invasive?
no, yes
what are the risks of TMS? ERP?
- muscle twitches, seizures,
- gel in hair
frames per second
temporal resolution
how is ERP data typically analyzed?
difference in average response between conditions time-locked to an event
how is fMRI data typically analyzed?
voxel by voxel, or multi-voxel pattern analysis
magnussen and stevens, and Thompson: early attempt at neurostimulation struggled to generate the necessary field strength. this is the history of what??
TMS
when was the first successful TMS on the human brain? what was it on?
1985, on motor cortex
- by barker, jalinous and freeston
—– manipulates brain by inducing neural activity
TMS
is TMS localized? it is specific?
yes, no
TMS can activate regions inducing? and inhibit regions inducing?
- muscle movements, phosphenes
- impaired movements, scotomas
what are 6 risks of TMS
- seizure induction
- Hearing loss (loud click- 90-130dB, 2-7hz)
- local neck pain and headaches (stim of local muscles and nerves) (frontotemporal regions particularly)
- Effect on mood in normal (site and freq dependent)
- Long term effects
- Effect on cognition (better verbal mem, improved delayed recall ad better rxn time)
high freq of TMS to what lobes may worsen and better mood?
- left frontal = worsen
- right frontal - improve
what TMS coil type is more ideal?
the 2- donught shaped one because the electrical field strength is localized in the middle of the 2 where they meet
aas frequency of TMS (hz) increases, what happens to duration?
it decreases, not safe otherwise
what are contraindications to TMS?
- metallic hardware near coil
- history of seizures
- medicines which reduce seizure threshold
- pregnancy
- previous head trauma
- substance abuse
- brain surgery
- other medical/neurological disorders
4 guidelines to conducting TMS (prior to testing)
- safety screening
- informed consent (disclosure of all significant risks)
- potential benefit must outweigh risk
- equal distribution of risk
(vulnerable population should be avoided)
what is the temporal resolution of single pulse TMS? and for rTMS?
- 1 ms
- depends on duration of pulse train –> ranging from <1s - 1 min
what is often used as a reference point for intensity of TMS
motor threshold (lowest power needed to induce a movement)
what areas can you not stimulate?
medial or subcortical areas
why might effects not be localized?
spread of activation
- connected effects (multiple areas activate when one is stimulated) and paradoxical effects (interfering with one area can show improvements in other areas)
describe how one would use TMS to map in space
move the TMS around zapping different areas of the brain in order to map out how the brain is organized (lesioning different parts
describe how one would use TMS to map in time
look at when things are happening instead of where, ie, how long after a stimulus is given does the motor cortex activate
inferring timing of neural processing
chronometry
infer the role of brain area by resulting deficit
virtual lesion
infer connectivity between brain areas by effects of spreading activation
functional connectivity
