Although interest about the workings of the mind date back to the Ancient Greeks, the modern offshoot that established it as science rather than philosophy was based on the German School proponents of the Gestalt perspective. This branch of psychology states that behaviors are not an additive response to sensory stimuli. In effect, Gestalt psychologists clearly differentiated sensation (information collected by our senses) from perception (the way we think about our collected sensory experience).

According to Gestalt psychologists we all experience a physical world that bombards our senses with information. However, the way we interpret sensory information may differ among individuals. The difference between sensation and perception is quite evident when observing behaviors among different animal species. Bats hear ultrasonic sound and use these high frequency waves to navigate their surroundings. Cats hear the high pitch communication of rodents and although having keen night vision they lack the ability to distinguish different colors. Dogs, on the other hand, have a keen sense of smell and rely on this sense just as much as humans rely on vision. Indeed all of these species live in the same physical world but have different perceptions of the same.

Changes in our ability to sense the environment permeate our perception of the same. It is our perceptions that gives meaning to our sensory world and provides our reality (not the environmental or geographical reality but the one recognized by our brains). This ability to perceive is based on the configuration of our nervous system. It is for this reason that changing the bias of excitation/inhibition within the central nervous system may have a profound effect in our day-to-day life.

John Ratey (a psychiatrist from Harvard) has written several books using this bias in cortical stimulation as an explanation for what at first instance would be misclassified as “maladaptive” behaviors (see “Driven to Distraction” and “Shadow Syndromes”). According to Dr. Ratey a hyperactive/hyperarousable brain provides for inattention, concreteness of our thought process, and a resurgence of primitive behaviors such as tantrums. People so affected usually misread social cues and thus shy away from social interaction, they develop a ruminative self-focus, and are prone to develop a disorder of affect (depression/anxiety). Not surprisingly many of these people have a behavioral phenotype consistent with Attention Deficit Hyperactivity Disorder.

Our studies on autism spectrum disorders (ASD) have shown changes in the cerebral cortex that could explain how signals fall into an amplification cascade. We have proposed that there is a desynchronization in the maturation of excitatory and inhibitory neurons that explain the presence of seizures and sensory abnormalities in this condition (see http://bit.ly/1nvnJq0).

The cells that modify information transmission through the central nervous system are called neurons. These cells have receptive surfaces in their bodies where they receive information from other neurons. When the stimuli add up and go over a certain threshold that neuron will fire its own volley of information. In a hyperexcitable cortex, neurons are already stimulated making it easier for any incoming signal to trigger that cell to fire. In effect, the threshold for firing is lowered and so is the distinction between noise and signal. In this state what would have otherwise been an innocuous signal has an impact on the central nervous system. This hardwiring of the brain is likely to color the way we perceive the world and thus provide a susceptibility towards a particular cognitive personality style (see Williams and Casanova, 2010).

References

Williams EL, Casanova MF. Autism and dyslexia: a spectrum of cognitive styles as defined by minicolumnar morphometry. Med Hypothesis 74(1):59-62, 2010.