Attentional Searchlight - Deepstash





To Pay Attention, the Brain Uses Filters, Not a Spotlight | Quanta Magazine

Attentional Searchlight

  • While the prefrontal cortex region of the brain had long been studied by neuroscientists, a separate region of the brain, called thalamus came in the picture in 1984, by a new theory that suggested that the region acts as a gatekeeper of the senses, apart from being a relay centre.
  • The region has a thin layer of inhibitory neurons wrapped around it, called the thalamic reticular nucleus(TRN), which acted as ‘gates’ and hid or removed some of the data that is not required at a given time, to establish a level of focus for the individual.
  • The study found that the brain was lowering the unwanted signals to help us focus on the stimuli of interest.




The first views on motivation
The first views on motivation
  • At first, psychologist William James thought that only the initial act was conscious, thereafter behaviour was a spontaneous cascade of habits. He suggested we struggle with motivation when ...
Mathematics of motivation

When Ivan Pavlov and his dogs led to the discovery of learned behaviour through repeated exposure, and Edward Thorndike discovered the Law of Effect that stated that rewarded behaviours tended to increase, many psychologists were impelled to separate psychology from armchair introspection and formulated their theories as mathematical formulas.

  • The Drive x Habit Theory. Clark Hull's formula was sEr = D x sHr, which states that excitatory tendency (E) is the result of the drive (D) combined with the habit (H). The drive is nonspecific, such as hunger or thirst. The habit, however, depends on the stimulus (s) and response (r). But the theory turned out to be wrong and even opposite in many cases. 
  • Expectation x Value Theory. Drawing on ideas in economics and game theory, Edward Tolman and Kurt Lewis formulated an alternative account by evaluating motivation based on expectations. Tolman expressed the ideas as the mathematical formula: Subjective Expected Utility = Probability1 * Utility1 + P2U2 + P3U3 + … where subjective expected utility of an action equalled the motivation to act. But, if you expect a reward, why act and not simply passively wait for the expected reward? 
Motivation as change

Donald Hebb realised that existing theories were too focused on reacting to the immediate environment. Thoughts, ideas and goals could be just as strong for triggering action as sights and sounds.

Together with John Atkinson, they noted that the study of motivation had undergone a "paradigm shift", where motivation couldn't be seen as how actions get started, but how the organism decides to change its behaviour from one thing to another.

Motivation to learn
Motivation to learn

As people get older, they often lose their motivation to learn new things. This get-up-and-go attitude is vital for our social well-being and learning.

In order to survive, we need to be ab...

Loss of motivation

Many mental health disorders can skew the ability to evaluate the cost and rewards of an action, such as anxiety and depression.

A depressed person may undervalue potentially rewarding experiences.

Improving cost-benefit motivation

Neuroscientists have now identified a brain circuit that is critical for maintaining cost and reward motivation.

Researchers are working on possible drug treatments that could stimulate this circuit. They suggest that training patients to enhance activity in this circuit through biofeedback could offer another potential way to improve their cost-benefit evaluations.