Commercial eggs produced from different housing systems. In the production of commercial eggs in Europe, four different types of housing systems for the chickens are used: cage, barn, free range, and organic. The characteristics of eggs produced from the four housing systems were investigated in Food Chemistry (Vol. 106, 2008). Twenty-eight commercial grade A eggs were randomly selected from supermarkets—10 of which were produced in cages, 6 in barns, 6 with free range, and 6 organic. A number of quantitative characteristics were measured for each egg, including shell thickness (millimeters), whipping capacity (percent overrun), and penetration strength (newtons). The data (simulated from summary statistics provided in the journal article) are saved in the accompanying file. For each characteristic, the researchers compared the means of the four housing systems. Minitab descriptive statistics and ANOVA printouts for each characteristic are shown (next column). Fully interpret the results. Identify the characteristics for which the housing systems differ.
Chapter 3 Elicited behaviors – behavior that happens in response to some environmental event Innate vs. learned behaviors Reflexes involuntary and automatic response (unlearned) - Pathway from sensory stimulus to motor response > processing handled solely by spine - Palmar grasp, eye blink, knee jerk, diving reflex Reflex Arc – nerve pathway involved in a reflex action Includes sensory and motor nerve w/ a synapse between Habituation – decreasing responses to a frequent bur innocuous stimulus Sensitization – increasing responses to a noxious/arousing stimulus Dishabituation – renewal of a response, previously habituated, that occurs when the organism is resented w/ novel stimulus Stimulus intensity – the strength of stimuli ex. Getting punched > if it hurt (high intensity), if it didn’t hurt (low intensity) Dual Process Theory – habituation and sensitization are independent of each other but operate parallel > good at explaining short term habituation Evolutionary perspective/advantage Opposing Reactivity Opponent Process Theory of Emotions – habituation and sensitization represent two opposing tendencies of reactivity > strong vs. weak Ex. Lotto ticket / roller coaster > both events elicited strong emotional response but when event was withdrawn, an opposite response was elicited and then gradually disappeared Habituation Neural Process – activated by every presentation of a stimulus - Occur in SR System > analogous of reflex arc Sensitization Neural Process only activated by arousing events - Occur in the State system > determines the animal’s general level of responsiveness or “arousal” * Whether we habituate or sensitize will depend upon which is stronger in given set of circumstance Types of learning: - Mere Exposure learning: perceptual learning without explicit training - Perceptual learning: experience w/ a set of stimuli makes the same stimuli easier to distinguish > increased ability to make fine distinctions Discrimination Training – Spatial Learning/ Tinbergen – acquisition of information about one’s surroundings - Hippocampal place cells: special neurons involved in navigation in space - Cognitive map: mental representation of the layout of one’s environment Priming/ Bluejays Novel Object Recognition – test for recognition memory Aplysia/habituation/sensitization - Habituation: repeated touch depletes sensory neuron of transmitter (synaptic depression) - Gentle touch to siphon, produces gill withdrawal > repeat every minute for 1015 min > progressively shorter with durations > recovers quickly but w/ many sessions becomes longlasting - Sensitization: tail shock activates interneurons that release serotonin > serotonin modulates sensory neurons to release more transmitter onto next activation - Gentle touch produces gill withdrawal > aversive shock to tail > next touch much longer withdrawal duration > recovers quickly but becomes long lasting w/ multiple sessions Cortical plasticity: refinement in the receptive fields of neurons of the sensory cortex due to development or experience Plasicity during development – brain changes with development and experience brain is consistently rewiring based on experience Hebbian learning – suggests an experienced based “natural selection” for most useful synaptic connections Homunculus/somatosensory cortex – pictorial representation of the primary somatosensory cortex Hippocampus & spatial learning London Taxi drivers study Cochlear implant Chapter 4 Classical conditioning US – food UR salivation CS – bell CR – response to conditioning Pavlov – physiological centers of learning US center – specific part of brain that becomes activated whenever US is present CS center – becomes activated during conditioning Response center – part of the brain responsible for every UR Appetitive conditioning – food is provided as a reward following the presentation of a stimulus Aversive conditioning – noxious stimuli are associated w/ undesirable or unwanted behavior that is to be modified or abolished (Ex. Nauseainducing drugs in treatment of alcoholism) Eyeblink conditioning – involves the pairing of a conditioned (usually a tone) stimulus to an unconditioned stimulus (air puff) > CR = blinking in response to tone Used to studysteural structures and mechanisms that underlie learning and memory Acquisition phase – 1 stage of learning when a response is established In classical condition, the period when the stimulus evokes the conditioned response Extinction – gradual weakening of a conditioned response that results in the behavior decreasing or disappearing Kamin's blocking effect – refers to failures of learning and/or the expression of classically conditioned responses when a target stimulus is presented Spontaneous recovery – refers to the reemergence of a previously extinguished conditioned response after a delay Timing in classical conditioning Simultaneous conditioning – conditioning that occurs frequently, unintentionally, or unplanned Delay conditioning – conditioned stimulus precedes the unconditioned stimulus by a significant time period and the organism learns to withhold its conditioned response Backward conditioning – behaviorconditioning method in which unconditioned stimulus (US) is presented before a neutral stimulus (NS) Latent inhibition – observation that a familiar stimulus takes longer to acquire meaning than a new stimulus Boy who cried wolf eventually ignored > when real wolf attacked, no one helped b/c “wolf” was not predictive RescorlaWagner model – organisms anticipate important events from the stimuli around them >learning a CSUS association depends on how much the US is expected - Sum of stimulus weights = animals prediction - When prediction is wrong, weights are adjusted > when error is 0, no learning occurs (ex. An injection hurt as much as you expected) Mackintosh Model CS – proposed a model of classical conditioning focused on attention and the way the CS is processed ISI – “interstimulus interval” / timing of presentation (timing in classical conditioning) Conditioned taste aversion – occurs when an animals associates the taste of a certain food w/ symptoms caused by a toxic, spoiled, or poisonous substance Physiological research / Aplysia – use to study habituation b/c it has only about 20,000 neurons that are hardwired, some of which are large enough to see w/ the naked eye Mammals/neural pathways Purkinje cells – neurons located in the cerebellar cortex Interpositus nucleus – involved in the formation & execution of the conditioned response Pontine nuclei – part of the pons involved in motor activity Climbing fibers –series of neuronal projections from inferior olivary nucleus located in brain Mossy fibers – 2 different bundles of axons in the brain 1) Cerebellum mossy fibers one of the major inputs to cerebellum Source of pathway is cerebral cortex 2) Hippocampus – unmyelinated axons project along mossy fibers Inferior olive – largest nucleus situation in the olivary body part (prominent olive structures in brain), of the brain * involved in motor control Humans /cerebellum Compensatory response model – bodies would compensate for burst of adrenaline (ex. Body would calm down and then adrenaline will rush but not too high > homeostasis balance Higher order conditioning – refers to a situation in which a stimulus that was previously neutral is paired with a condition stimulus to produce the same conditioned response as the conditioned stimulus Ex. tone that has been conditioning w/ food to produce salivation Brain Stimulation Cerebellar damage/Thompson studies Inhibitory feedback – situation in which the substances at the end of a long series of reactions inhibits a reaction at the beginning of the series of reactions Hippocampus & CS – removal of the hippocampus does not alter basic classical conditioning paradigms - Does eliminate latent inhibition - Disrupts other paradigms that depend on changes in the processing of the cs - US modulation occurs in the cerebellum (rescorlawagner) - CS modulation occurs in the hippocampus and medial temporal lobe Activitydependent enhancement – CS – weak sensory activation that primes the sensory neuron, but causes no further change US – serotonin release, but too weak to cause sensitization CS+US – primed sensory neuron responds to even a weak level of serotonin Synapses changes in learning CREB1/CREB2 CREB1: activated and promotes growth of new synapses CREB2: deactivated, as it inhibits growth of new synapses Clinical Significance drug addiction/abuse and Classical conditioning – environmental CS (ex. appearance and smell of drug taking location) produce CR drug craving in anticipation of US drug - Even subtle changes (Ex. To drug taste) can overrun tolerance and increase drug effects > increases possibility overdose - Administer the medication in a slightly different environment each time Bouton study (2002) – suggests that therapists conduct cueexposure therapy in different contexts including home Over varying time lengths with small amounts of drug use