Consciousness and Attention

1. Consciousness and Attention Yrd. Doç. Dr. Murat İlhan Atagün Department of Psychiarty

2. 1. Consciousness Awareness 1. General state of arousal (sleep vs. wakefulness) 2. Attentional focus or current awareness (watching football game or listening to wife)

3. Philosophy • Descartes • Mind is immaterial and totally separate from body (Pineal Gland) • Hume • Mind is not divine, but natural and physical. • Kant • Mind is physical, but has intuitions (Space and Time) • Mind processes and orders experience (Unity) • Minsky • Consciousness is one of those “suitcase-like” words that we use for many types of processes, and for different kinds of purposes

4. Higher-Level Consciousness controlled processing actively focus efforts toward a goal requires attention Lower-Level Consciousness Automatic processes • require little attention/conscious effort • do not interfere with other ongoing activities Daydreaming • wandering thoughts • fantasy, imagination, rumination • potentially useful (reminding, solving)

5. Cognitive Approaches 1. Attentional focus: selective attention 2. Automatic vs. Controlled processing 3. Implicit vs. Explicit memory • Recall test vs. Perceptual Identification test • Effects of priming

6. Biological Basis • Stream of information resulting from the activity of the thalamus which analyzes and interprets information • Consciousness may only be the “tip of the iceberg” that includes unconscious mental activities • Consciousness is also viewed as an adaptation allowing us to get along with others in our group (humans)

7. Altered States of Consciousness • Drugs • Fatigue, illness, trauma, deprivation • Meditation, hypnosis • Mental disorders

8. Subjects with Brain Lessions Blindsight: loss of visual consciousness due to damage to primary visual cortex Prosopagnosia: loss of face recognition due to damage to temporal lobe visual pathway.

9. Stages of Sleep • NREM (Non-Rapid-Eye-Movement) Sleep: • Stage 1 (lightest sleep) • Stage 2 (deeper sleep) • Stages 3 and 4 (deepest sleep) • REM (Rapid-Eye-Movement) Sleep

10. Sleep Disorders • insomnia • sleep walking, talking, and eating • nightmares and night terrors • narcolepsy • sleep apnea

11. Meditation Group of techniques designed to • Refocus attention • Block out all distractions • Produce an ASC

12. Hypnosis A state of heightened suggestibility, deep relaxation, and intense focus.. is used to treat chronic pain, severe burns, dentistry, childbirth, psychotherapy

13. 2. Attention • Selectively focusing on an object in an environment.. Most basic cognitive function • Allocation of resources to process a particular information • Very basic brain function that often is a precursor to all other cognitive functions.

14. Types of Attention • Selective attention • Divided attention (multitasking)

15. Clinical Types • Focused attention: the ability to respond to a specific stimulus • Sustained attention: The ability to maintain attention during a continuous activity • Selective attention: The ability to maintain attention focused among multiple stimuli • Alternating attention: Shifting attention from one focus to another • Divided attention: Processing multiple stimuli. Highest level of attention

16. Processing Load • If we receive multiple stimuli, we focus on our target stimulus and ignore the rest. • Number of stimuli we perceive decreases with advance of age • But older people process with more intense attention

17. Biological Base • Attention increases activation energy of the brain regions: a stimulus can arise an activity and if the subject focuses on the activity, then activation energy becomes increased • Working memory is the temporarily keeps the information for analysis

18. Bottom-up Processing • Stimulus driven attention (exogenous) • Attention to objects’ properties, unintentional attention controlled by the object • A sudden noise.. • The parietal cortex, temporal cortex and brain stem are related with bottom-up processing

19. Top-down processing • Volitional attention, under control of a person • Goal driven / endogenous attention • Frontal cortex and basal ganglia

20. Bottom-up vs Top-down • Filters enhance the response to non-target stimuli • Higher processes can regulate signal intensity in information channels of the brain and compete for accessing to working memory, and provide an advantage for the selected processing of the target stimulus

21. At different hierarchical levels spatial maps can enhance or inhibit activity in sensory areas, and induce orienting behaviors like eye movements • Focused attention produces gamma waves (30-70 Hz) in the brain

22. Functional components of attention • Alerting: Becoming and sustaining attentive. Right frontal and parietal lobes are responsible. Norepinephrine • Orienting: Directing attention to a specific stimulus • Executive attention: Gathering multiple information and resolving conflicts. The anterior cingulate cortex..

23. Perception

25. Perceiving and interpretation of sensory information in order to produce mental representations of the external world • 5 perceptive modalities: vision, audition, olfaction, tasting and somatic sensation (touching) • Chemical or physical mechanisms serve for these sense organs (photons striking to retina or odor molecules for smelling, pressure for hearing..)

26. Top-down influences on perception • Learning • Memory • Expectation • Attention

27. Mooney Faces

28. Fundamentals • Perceptual systems of the brain enable people to perceive the world stable even the information is not complete or variable.. • Different brain regions process different sensory information (occipital lobes visual, temporal lobes auditory..) • Some of these different systems are interconnected: visual and auditory systems are connected, odor and taste centers are connected

29. Fundamentals • Depth perception consists of processing of many visual information, each of which is based on a regularity of the physical world • Vision responds to the electromagnetic energy, that does not pass through objects • Sound waves provide information about the sources and distances of the objects. • Taste and smell receive the chemicals in the environment • Sense of touch consist of many senses: pressure, pain, cold-heat…

30. Stages • Distal stimulus (object): an object from the real world • Physical stimulus arrives to sensory organ • Transduction: Sensory organ transform the energy into neural activity • This raw pattern of neural activity is called proximal stimulus • These neural activities are transmitted to the involved brain regions and processed and become percept

31. Other aspects • Encountering an unfamiliar target causes increasing attention, collect different informational cues, want to learn much about the target. When we have enough information we categorize the object.. • Experiences, motivation and emotional state can influence perceptive abilities.. • An ambiguous stimulus may be translated into multiple percepts: multistable perception

32. Physiology • Sensory system: Part of the nervous system responsible for processing sensory information • Sensory receptors, neural pathways, parts of the brain involved in perception • The specific part of the world that is in the area we can perceive is receptive field… (visual field)

33. Vision • Light sensitive membrane (retina) on the back of the eye is the first place of sight • Transduction of the received information is complex • Neural activity is transmitted to occipital cortex • And processed with different parts of the cortex

34. Hearing (Audition) • Perceive sound by detecting vibrations (waves) • Frequencies between 20 – 20000 Hz is the band we can hear • Ears, inner structures; neural pathways; primary and secondary auditory cortices on superior temporal cortices and their associations • Hearing is a complex function that discriminate sounds from different multiple sources and directions. This is a computational task of discriminating sources and estimating distance, tone, emotional prosody of the sound…

36. Touching (Haptic Perception) • Recognizing objects through touch • A combination of somatosensory perception on the skin surface and proprioception and conformation

37. Taste (Gustation) • Ability to perceive the flavor of substances • Receptors are concentrated on the upper surface of the tongue, there are 100-150 types of receptor types • Sweetness, bitterness, sourness, saltiness are main tastes, other tastes are combination of these tastes