Theories* The subject-expectancy effect and classical conditioning are pretty similar. In both, the patient has a built-in expectation of the outcome.

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1 Placebo Effect* Occurs if patients given a placebo treatment will have a perceived or actual improvement in a medical condition a wide variety of things can be placebos and exhibit a placebo effect. Pharmacological substances administered through any means can act as placebos, including pills, creams, inhalants, and injections. Medical devices such as ultrasound can act as placebos. Sham surgery and sham acupuncture, either with sham needles or on fake acupuncture points, have all exhibited placebo effects.

2 Theories* One theory behind the placebo effect is the subject-expectancy effect. When people already know what the result of taking a pill is supposed to be, they might unconsciously change their reaction to bring about that result, or simply report that result as the outcome even if it wasn't. Others believe that people who experience the placebo effect have become classically conditioned to expect relief when they take medication. In the case of people and placebos, the stimulus is the medicine (or what's perceived to be medicine) and the response is relief from their symptoms. The subject-expectancy effect and classical conditioning are pretty similar. In both, the patient has a built-in expectation of the outcome.

3 Neurological Basis for Placbeo effect* In 2004 it was demonstrated that the placebo effect is related to endorphins, the brain's own natural pain relievers healthy subjects were given a painful but harmless injection in the jaw while their brains were scanned The subjects were then given what they thought was a pain reliever, and all of them experienced a decrease in their pain levels after receiving the placebo. they also showed a change in brain activity in the brain's opioid receptors (which receive endorphins) and its areas related to processing and responding to pain. That is why the naloxone mentioned before has an effect The expectation of pain relief caused the brain's pain relief system to activate.

4 A well controlled study* Operated patients were treated with a powerful pain reliever on request for 3 consecutive days, together with a intravenous infusion of saline solution. The symbolic meaning of this saline infusion was changed in three different groups of patients. The first group was told nothing about any analgesic effect (natural history). The second group (two parts) was told that the saline was either a powerful painkiller or a placebo (classic double-blind administration). The third group was told that the saline infusion was a potent painkiller (deceptive administration).

5 Brain reconstruction* Rather than pictures in the brain -Hubel & Weisel -nobel prize receptive fields from different parts of visual field - cells respond not to dots of light (like visual pointillism of Seurat A Sunday Afternoon on the Island of La Grande Jatt) but rather edges, contrast This is what the world looks like in the early processing in the visual cortex- before it is seen - more like Cézanne (Forest with the rock caves above the Château Noir)

6 Seeing* The practical human brain is not interested in a cameralike truth - it wants the scene to make sense. From the earliest levels of visual processing in the brain to the final polished image, coherence and contrast are stressed - often at the expense of accuracy In essence what we end up perceiving is influenced by a top-down process- cortical brain layers project down and influence our actual sensations-the outside world is forced to conform to our expectations

7 Perceptual constancy* tendency see familiar objects as having standard shape, size, colour, or location regardless of changes in the angle of perspective, distance, or lighting. The impression tends to conform to the object as it is or is assumed to be, rather than to the actual stimulus. Perceptual constancy is responsible for the ability to identify objects under various conditions, which seem to be "taken into account" during a process of mental reconstitution of the known image.

8 Colour perception* 3 types of Cones in retina different wavelengths cause chemical changes in different cones. Opponent colours: Red-green; blue- yellow; black-white. Essentially when a wavelength of one of the pairs stimulates the appropriate cone, perception arises from a chemical reaction in one direction, the perception of the other member of the pair is antagonistic.