Henry Family Blog

Did you ever wonder why or how your body makes certain movements?  How you adapt to the world around you?  How you can think about walking and then your legs just start doing the motions?  How your heart beats without you telling it to do so?  Interesting huh?

It all boils down to information processing.  There is sensory information inside of you and in your outside environment.  This information must be processed by your Central Nervous System.  Your Central Nervous System is similar to a computer.  The information that goes into your brain (computer) is processed and used to generate an appropriate output.  With the processing of this information, there is a reaction time.  A reaction time is when there is a delay between the presentation of the stimulus and the initial response. 

There are three stages of information processing.  The first is stimulus identification.  A stimulus must be recognized.  Second, a response selection.  Your body determines what response is appropriate.  Finally, response initiating and programming.  Your neuromuscular system must be primed and your motor response initiated.

Donders’ Subtractive Method

This study is evidence of information processing.  Three tasks were given to subjects with increasing complexity. 

1. Simple Reaction Time

     -Visual stimulus and simple reaction task.  e.g. Press a key with the right index finger after a light stimulus.

2. Go/No Go Reactions Time

      -e.g. 2 light stimuli; red=”go”, blue=”no go”

3. Choice Reaction Time 

      -e.g. 2 light stimuli; red=”right”, blue=”left”

The results:  As your movement complexity increases, so does your reaction time.  Meaning, there are more stages of processing.   There is also serial and parallel processing.  Donder suggests that information is processed in a serial (sequential) manner.  He also suggests that it occurs in parallel (simultaneously.)

Stimulus Identification 

Going back to the stimulus identification stage, there are two sub-stages; stimulus detection and pattern recognition.  Stimulus detection involves sensory organs detecting and transmitting stimulus specific information.  The signal must be interpreted and the inherent meaning of sensory information determined.  Pattern recognition is when most movement tasks are associated with multiple stimuli.  The inter-related stimuli is typically presented in a prescribed pattern.  Recognition of this pattern is essential for a proper neuromuscular  response.

Response Selection Stage

This stage is the determination of the appropriate response influenced by environmental clues.  The time required to determine the appropriate response is dependent on three things.  They are number of stimulus-response alternatives, stimulus-response compatibility and simon effects. 

Hick’s Law is as the number of response alternatives increase, so does the choice reaction time.   The time required to choose a response linearly is related to the amount of information that must be processed in making a decision.  There are many exceptions to Hick’s Law.

In stimulus-response compatibility, spatial relationship is the most important in determining the choice reaction time.  The choice reaction time is shorter with spatial compatibility. 

Simon effects, the influence of the stimulus-response compatibility on choice reaction time persists when the spatial dimension of the stimulus is irrelevant to the response selection.  The irrelevant spatial presentation of the stimulus greatly influenced the choice reaction time.

Response Programming Stage

This is the final stage of information processing.  It cannot be initiated until the stimulus is identified and the appropriate response is selected.  Most voluntary responses are complex in nature and retrieved from our motor memory.  They are feedforward.

Tags: Education //