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Posner devised a scheme of using valid and invalid cues across trials. In valid trials, the stimulus is presented in the area as indicated by the cue. For example, if the cue was an arrow pointing to the right, the subsequent stimulus indeed did appear in the box on the right.
IOR was first described in depth by Michael Posner and Yoav Cohen, [1] who discovered that, contrary to their expectations, reaction times (RT) to detect objects appearing in previously cued locations were initially faster to validly cued location (known as the validity effect), but then after a period of around 300 ms, response times to a previously cued location were longer than to uncued ...
For example in a lexical decision task a participant observes a string of characters and must respond whether the string is a "word" or "non-word". Another example is the random dot kinetogram task, in which a participant must decide whether a group of moving dots are predominately moving "left" or "right".
In Posner's cueing paradigm, [4] the task was to detect a target that could be presented in one of two locations and respond as quickly as possible. At the start of each trial, a cue is presented that either indicates the location of the target (valid cue) or indicates the incorrect location thus misdirecting the observer (invalid cue).
Posner's model of attention includes a posterior attentional system involved in the disengagement of stimuli via the parietal cortex, the shifting of attention via the superior colliculus and the engagement of a new target via the pulvinar. The anterior attentional system is involved in detecting salient stimuli and preparing motor responses.
Example graph of the power law, x axis represents time, y axis represents reaction time. The power law of practice states that the logarithm of the reaction time for a particular task decreases linearly with the logarithm of the number of practice trials taken. It is an example of the learning curve effect on performance.
Can we imagine ourselves back on that awful day in the summer of 2010, in the hot firefight that went on for nine hours? Men frenzied with exhaustion and reckless exuberance, eyes and throats burning from dust and smoke, in a battle that erupted after Taliban insurgents castrated a young boy in the village, knowing his family would summon nearby Marines for help and the Marines would come ...
Cue validity is the conditional probability that an object falls in a particular category given a particular feature or cue. The term was popularized by Beach (1964) , Reed (1972) and especially by Eleanor Rosch in her investigations of the acquisition of so-called basic categories ( Rosch & Mervis 1975 ; Rosch 1978 ).