(a) William James’s suggestion that the infant’s world is a “buzzing, blooming, confusion”
gives the impression that the infant, at least temporarily, inhabits a psy-
chological world.(b) The sharpening of a perception on repeated presentations of a stimulus can be attrib-
uted to.Answers: (a) chaotic; (b) learning.One way to explain this sharpening of perception is to suggest that patterns of
stimulation set off chain reactions in neurons located, let us say, in the association
areas of the brain’s cortex. Each time a given stimulus is presented, the same set of
neurons fire. The research of the Canadian psychologist Donald O. Hebb suggests
that repeated firings form a cell assembly,a stable group of neurons that are used
over and over by the brain to create a representation of the external pattern. A pat-
tern can, of course, be quite complex. If this is so, a given cell assembly may rep-
resent only a portion of a pattern. Hebb called a set of cell assemblies grouped
together to form a larger pattern a phase sequence.
The existence of cell assemblies helps account for a memory of patterns and
perceptual objects. When you hear a melody or recognize something you have
seen before, it is quite possibly because an established cell assembly is firing.
Learning also plays a role in perception because we are conscious beings who
attach labels to perceptual objects. This brings us to the cognitive hypothesisin
perception, the hypothesis that we not only perceive, but know what we are per-
ceiving. If you see a friend and think, “There’s Erin,” or hear a song and think,
“That’s ‘God Bless America’ by Irving Berlin,” then you have increased the acuity
of your perceptual world. Cognitive learning,learning in which consciousness
plays an important role, is an important aspect of the perceptual process. There is
more about learning in general and cognitive learning in particular in chapter 6.(a) According to Hebb, a cell assembly is a stable group of.(b) The hypothesis that we not only perceive, but know we perceive is called the
.Answers: (a) neurons; (b) cognitive hypothesis.Illusions: What Do They Teach Us about Perception?
An illusionis a false perception, a perception that does not fit an objective
description of a stimulus situation. An illusion is usually associated with a partic-
ular sense. Consequently, there are optical illusions, auditory illusions, and so
forth. Illusions tend to be remarkably stable. They affect most normal observers in62 PSYCHOLOGY