PSYC 213CognitionJan 18 - Visual perception: Physiology and Awareness Last class: ●Functional specialization: Different areas of the brain support different functions, The idea of localization / Modularity and phrenology●Opposition to functional specialization: Franz and Lashley / Mental processes relate to activity of the brain as a whole, and not individual parts.The mind-brain link●Interactionism: The mind and brain are separate entities that interact and influence each other.●Epiphenomenalism: Mental events are caused by physical events.●Parallelism: The mind and brain are two aspects of the same reality.●Isomorphism: The correspondence between mind (consciousness) and the brain isStructural.Cognitive neuroscience methods●Animal Models●Human Psychophysiological Experiments●Neuropsychology Cases: Split brain patients.●Neuroimaging Techniques: EEG methods: Good temporal resolution / PET: Use of radioactive tracers to measure brain metabolism / fMRI: Good spatial resolution to measure brain activity / MEG: Temporal and spatial resolution, but the signal decay / Brain stimulation techniques: Temporarily impair/enhance brain function.Timing versus Location●MEG/EEG – brain activity at the level of the millisecond●PET/fMRI – brain activity at the level of the millimeterBrain stimulation●Review: TMS is a procedure in which brain activity is influenced by a magnetic field, either increasing or decreasing the brain’s electrical signals. This results in behavioral changes.●Related: Deep brain stimulation (DBS). Implant tiny electrodes in the brainto send an weak and constant electrical current to targeted regions of the brain / Reduces symptoms in cases like depression, Parkinson's / Mechanisms not known.This class: Perception●Sensations and Perceptions.●Physiology of Visual Perception: How information travels from the eyes to the brain.●Perception with and without awareness: Conscious and unconscious processes.●Visual Illusions: Visual perception is constructive and relies on assumptions.Sensation to perception●Stimulus energy → Sensory receptors → Neural impulses --------------→ Brain → Sensations -------------------------------------------------------→ Perception ------→ Confusing the senses: Synaesthesia1
PSYC 213Cognition●Stimulation of one sense simultaneously produces another sensation in a different modality.●For example: Grapheme-color synesthesia. Seeing certain numbers or letters as certain colors.McGurk Effect: Hearing Lips●Speech sound /ba/ simultaneously presented with visual speech sound /fa/ heard as /fa/.●A multisensory illusion: a change in auditory perception from visual input.●Demonstrates two concepts: The integration of sensory information. *The power of visual input*: It overrides audio input!