How does sensation influence perception

What does it mean to sense something? Sensory receptors are specialized neurons that respond to specific types of stimuli. When sensory information is detected by a sensory receptor, sensation has occurred. For example, light that enters the eye causes chemical changes in cells that line the back of the eye.

These cells relay messages, in the form of action potentials as you learned when studying biopsychology , to the central nervous system.

The conversion from sensory stimulus energy to action potential is known as transduction. You have probably known since elementary school that we have five senses: vision, hearing audition , smell olfaction , taste gustation , and touch somatosensation. It turns out that this notion of five senses is oversimplified. We also have sensory systems that provide information about balance the vestibular sense , body position and movement proprioception and kinesthesia , pain nociception , and temperature thermoception.

Figure 1. The absolute threshold for detecting light is greater than you probably imagined—the human eye can see a candle on a clear night up to 30 miles away! The sensitivity of a given sensory system to the relevant stimuli can be expressed as an absolute threshold. Another way to think about this is by asking how dim can a light be or how soft can a sound be and still be detected half of the time.

The sensitivity of our sensory receptors can be quite amazing. Under quiet conditions, the hair cells the receptor cells of the inner ear can detect the tick of a clock 20 feet away Galanter, It is also possible for us to get messages that are presented below the threshold for conscious awareness—these are called subliminal messages. A stimulus reaches a physiological threshold when it is strong enough to excite sensory receptors and send nerve impulses to the brain: this is an absolute threshold.

A message below that threshold is said to be subliminal: we receive it, but we are not consciously aware of it. Therefore, the message is sensed, but for whatever reason, it has not been selected for processing in working or short-term memory. Over the years there has been a great deal of speculation about the use of subliminal messages in advertising, rock music, and self-help audio programs.

Research evidence shows that in laboratory settings, people can process and respond to information outside of awareness. Figure 2. Priming can be used to improve intellectual test performance. Research subjects primed with the stereotype of a professor — a sort of intellectual role model — outperformed those primed with an anti-intellectual stereotype.

These days, most scientific research on unconscious processes is aimed at showing that people do not need consciousness for certain psychological processes or behaviors.

One such example is attitude formation. The most basic process of attitude formation is through mere exposure Zajonc, Merely perceiving a stimulus repeatedly, such as a brand on a billboard one passes every day or a song that is played on the radio frequently, renders it more positive. Interestingly, mere exposure does not require conscious awareness of the object of an attitude. In fact, mere-exposure effects occur even when novel stimuli are presented subliminally for extremely brief durations e.

Intriguingly, in such subliminal mere-exposure experiments, participants indicate a preference for, or a positive attitude towards, stimuli they do not consciously remember being exposed to.

Another example of modern research on unconscious processes is research on priming. Priming generally relies on supraliminal stimuli, which means that the messaging may occur out of awareness, but it is still perceived, unlike subliminal messaging. Supraliminal messages are be perceived by the conscious mind. For example, in one study, shoppers listened to either French or German music the supraliminal messaging while buying wine, and sales originating from either country were higher when music from that same country was played overhead.

These lists contained words commonly associated with the elderly e. The remaining participants received a language task in which the critical words were replaced by words not related to the elderly. After participants had finished they were told the experiment was over, but they were secretly monitored to see how long they took to walk to the nearest elevator. The primed participants took significantly longer. That is, after being exposed to words typically associated with being old, they behaved in line with the stereotype of old people: being slow.

Such priming effects have been shown in other domains as well. For example, Dijksterhuis and van Knippenberg demonstrated that priming can improve intellectual performance.

They asked their participants to answer 42 general knowledge questions taken from the game Trivial Pursuit. This is when we build up to perception from the individual pieces. This is called top-down processing. The best way to illustrate these two concepts is with our ability to read.

Notice anything odd while you were reading the text in the triangle? In other words, your past experience has changed the way you perceive the writing in the triangle. Someone who is just learning to read is using a bottom-up approach by carefully attending to each piece and would be less likely to make this error. Sensation The physical process during which our sensory organs e. Perception is the process of interpreting the information acquired through the five senses accordingly.

The source of sensation is the stimuli obtained from sensory organs whereas the source of perception is the information sent to the brain through sensation. Sensation results in perception, which results in interpreting and giving meaning to the information received. Sensation and perception are basic phenomena in us that happen throughout our life. Sensation basically refers to the process of sensing our environment using the stimuli we obtain from our five senses, on the other hand, perception refers to the process of interpreting those stimuli to meaningful information.

Thus, perception typically follows sensation. This is the basic difference between sensation and perception. Upen, BA Honours in Languages and Linguistics, has academic experiences and knowledge on international relations and politics.

Figure 1: Five Senses. Figure Perception. View all posts.