Biopsychology Flashcards
Biopsychology
A branch of psychology that studies how the brain and neurotransmitters influence our behaviours, thoughts and feelings. Looks how the biological processes interact with emotions, cognitive and other mental processes. The key components are: brain, neurotransmitters and nervous system.
Central Nervous System (CNS)
Made up of the brain and spinal cord.
It passes messages to and from the brain and connects nerves to the PNS.
Peripheral Nervous System
It’s further subdivided into the autonomic nervous system and somatic nervous system. The PNS transmits messages via neurons to and from the CNS.
Somatic Nervous System
It controls movement of the mus les and receives information from sensory receptors.
Automatic Nervous System
Governs vital functions in the body such as breathing and heart rate etc.
Sympathetic Nervous System
This is responsible for preparing the body for fight or flight.
Nervous System
This is the network of nerve cells and fibres which transmits nerve impulses between parts of the body.
Parasympathetic Nervous System
This is responsible for restoring the body to resting levels.
Brain
An organ which is the coordinating centre of sensation, intellectual and nervous activity.
Spinal Cord
A bundle of nerve fibres that connects the brain to the rest of the body.
Sensory Neurons
Found in receptors such as skin and carry nerve impulses to the spinal cord and the brain. When the nerve impulses reach to the brain, they’re translated as sensations such as vision, taste, etc. However, not all sensory neurons reach the brain as some neurons stop at the spinal cord, allowing for quick reflex actions.
Relay Neurons
Found between sensory input and motor output or response. Relay neurons are found in the brain and spinal cord, allowing sensory and motor neurons to communicate.
Motor Neurons
Found in the CNS and it controls the muscle movements. When motor neurons are stimulated they release neurotransmitters that are stimulated they release neurotransmitters that bind to the receptors on muscles to trigger a response, which lead to movement.
Synaptic connections
They can be excitatory or inhibitors. The difference lies in the actions of he neurotransmitters at the postsynaptic receptor.
The normal brain function relies on the balance of excitatory and inhibitors.
Excitatory
They make it more likely that the next neurons will fire (such as acetylcholine)
Inhibitory
They make it less likely that the next neurons will fire (such as GABA)
Synapse
The gap end between the end of 1 neuron and the dendrites of the next neuron.
Knee-jerk reflex
In a reflex arc, a stimulus such as the hormone hitting the knee is detected by sense organs in the peripheral nervous system, which sends a message to the sensory neuron.
The message reaches the CNS, where it connects with a relay neuron. This can transfer the message to a motor neuron. Then carries the message to an effector such as the muscles and causes the muscles to contract and hence, the knee to move or jerk.
Ways of investigating the brain
Functional magnetic resonance imaging (fMRI)
Electroencephalogram (EEG)
Event related potentials (ERPs)
Post-mortems
Techniques used for observing activities of the brain
Non-invasive
Invasive
Non-invasive
The technique that does not involve breaking the skin.
Invasive
Where the skin is broken to observe the brain.
Brain imaging technologies (concepts to know)
Spatial resolution
Temporal resolution
Spatial resolution
The resolution of the imaged produced.
Temporal resolution
How long it takes to take a frame. So how accurately charges in the brain can tackle.
Post-mortems
When a person’s body (including brain) is examined after death.
The brain is dissected and analysed to check to structural damage/abnormalities. Neurological abnormalities have been linked to depression, schizophrenia etc.
Can be used to explain behaviour exhibited by the individual prior to death.
Study: HM’s inability to store new memories was linked to lesions in hippocampus.
Strength: Useful - allows to learn the structure of the brain & behaviour.
Weakness: Only used in death cases - can’t make questions; No precision - to know of damaged was before the death or after; We don’t know if it affected the behaviours.
fMRI
A brain scanning that produces 3D images showing which parts of the brain are involved in a particular mental process.
It measures the increase of blood flow to brain sites when individuals are asked to perform cognitive/ physical tasks. Increased blood flows means increased demand for oxygen in that area.
It can help build a map of brain localisation.
Strength: Controlled conditions - can manipulate tasks; Excellent spatial extraneous - clear picture
Weakness: Expensive; Correlation not causation
Electroencephalogram (EGG)
It measures and records the electrical activity of the brain.
It works on the premises that information is processed in the brain as electrical activity in the form of action potentials or nerve impulses, transmitted along neurons.
EEG measures the electrical activity through the electrodes attached to the individual’s scalp. The small electrical charges are detected and graphed over a period of time - indicating the level of activity in the brain. In the sleep, wakefulness and arousal are the ways that allow us to analyse this.
Strengths: Presence of mental illness - epilepsy or alzheimer; Pinpoint locations of the brain - able to move comparisons of brain activity
Weakness: Lacks on precision - only measures general activity
Event Related Potentials (ERP)
It measures and records the electrical activity of your brain when presented with stimulus.
Used electrodes that are attached to the scalp (such as EGG). However, the difference is that a stimulus is presented to participants and the researcher looks for activity related to that stimulus.
Strength: Pinpoint the brain’s locations - looks at changes in the brain activity when stimulus is presented.
Weakness: Extraneous Variables - there could be control
Localisation of function of the brain
Hemisphere means half
Lateralisation means side
Hemisphere and the cerebral cortex
Brain is divided into 2 symmetrical halves called left and right hemisphere;
Some functions are dominated by one hemisphere (lateralisation);
Activity on left side of body is controlled by right hemisphere and vice-versa;
The outer layer of both hemispheres is called the cerebral cortex, 3 mm layer covering the inner parts of the brain;
This separates us from other animals;
Lobotomy
Surgical procedure in which the nerve pathways in a lobe or lobes of the brain are severed from those in other areas.
Broca’s Area
It’s in the frontal lobe. Critical for speech production.
Named after a french neurosurgeon, Paul Broca.
Study: Treated a patient, ‘Tan’ that knew language but was able to say 1 word. Studied 8 patients with similar features, along with lesions in their left frontal hemisphere. Patients with lesions in the right frontal hemisphere didn’t have the same problems.
The motor region in Broca’s area is closed to the area that controls mouth, tongue and vocal cords.
Findings: When a cognitive performance occurs (not language related) the Broca’s area activates.
Study: Fedorenko (2012) found 2 areas of the Broca’s area - 1 related to languages and another related to cognitive perform tasks ( eg:. Maths).
Broca’s area is responsible for LANGUAGE.
Wernicke’s Cortex
It’s at the back portion of temporal lobe.
German neurologist, Carl Wernicke.
Discovered an area of the brain involved in understanding language.
Patients with lesions in Wernicke’s area could speak but were unable to understand language.
Proposed that language involved separate motor and sensory regions located in different cortical regions.
In Wernicke’s area the sensory region is closed to areas that control the auditory and visual input - when information from these areas was transferred to Wernicke’s area, it was reorganised as language & associate meaning.
There’s a neural loop (arcuate fasciculos) running between Broca’s area and Wernicke’s area. In one end Wernicke’s area is responsible for SPOKEN LANGUAGE. And Broca’s area is responsible for LANGUAGE in the other end.
Visual Cortex
It’s in the occipital lobe.
Somatosensory Cortex
It’s in the Pariental lobe in the back of it.
Motor Cortex
It’s in the pariental lobe in the beginning of it.
Auditory & Language Cortex
It’s in the beginning of the temporal lobe.
Phineas Gage - Localisation Theory
Phineas Gage was in an explosion and was projected with a pole through is left cheek, passing behind the left eye and exiting his skull from the top of his head taking a portion of his brain with it - most of his left frontal lobe. He survived, however his personality was affected by it and he went from a calm and reserved person to quick tempered and rude.
It was found that the frontal lobe was responsible for mood regulations, showing localisation of the brain due that the brain has various areas for specific roles.
Strength: Supporting the evidence for language centres from aphasia studies; Allows for specific development of treatments
Weakness: Individual differences in language areas; Language production may not be confirmed to Broca’s area alone; Challenges to localisation - higher mental functions may not be localised.
Lateralisation (split-brain)
Split-brain patients are individuals who have undergone a surgical procedure where the corpus callosum, which connects the two hemispheres, is cut. This procedure, which separates the two hemispheres, was used as a treatment for severe epilepsy.
Sperry Study - lateralisation (split-brain)
Aim: To investigate the effects of hemispheric de-connection on perception and memory.
Sample: 11 patients who had commisurotomies to separate the left and right hemisphere. Sperry’s didn’t do commisurotomies.
Design: Quasi experiment, lab. Experiment. Tested in laboratory using apparatus that could display stimuli independently to the left and right visual field. Patients had to say, write or find what they had seen. Other testes used objects placed either separately or simultaneously in each hand, which pots had to name. Manual tests such as copying hand positions were also conducted.
Results: In split- brain patients, each hemisphere can perceive and remember information presented only to that hemisphere. Verbal responses were possible only when information was presented to the left hemisphere.
Conclusion: Hemisphere deconnection causes the 2 hemispheres to operate independently, each having its own consciousness, including perception, and memory. Produces a ‘doubling’ of conscious awareness, as each hemisphere is unaware of the other. The right hemisphere, although less linguist than the left can use logic.
Biological Rhythms
Biological rhythms are regular patterns of physiological, behavioural or cognitive activity.
There are 3 types:
Circadian, Infradian, Ultradian
Evaluating circadian rhythms - Siffre study
Research Support: Has been conducted to investigate circadian rhythms and the effect of external cues like light on this system.
Study: Siffre (1975) found that the absence of external cues significantly altered his circadian rhythm: When he returned from an underground stay with no clock or light. He believed the date to be a month earlier than it was. This suggests that his 24 hours sleep-wake cycle was increased by the lack of external cues, making him believe 1 day was longer that what it actually it was, leading to his thinking that fewer days has passed.
Evaluating circadian rhythms - Aschoff & Weber (1962)
Additional support for Siffer’s findings.
They studied ppts living in a bunker had no windows and only artificial light, which the ppts were free to turn on and off as they wish.
Findings: Ppts settled to a longer sleep-wake cycle of between 25-27 hours.
The studies suggest that humans use natural light (exogenous zeitgebers) to regulate a 24 hour circadian sleep-wake cycle, showing the importance of light.
Evaluating circadian rhythms - Buhr et al (2010)
Found that fluctuations in temperature set the timing in cells in the body and caused tissues and organs to become active or inactive. Buhr claimed that information about light levels is transformed into neural messages that set the body’s temperature. Body temperature fluctuates on a 24 hour circadian rhythm and even small changes in it can send a powerful signal to our body clocks. This shows that circadian rhythms are controlled and affected by several different factors, and suggests that a more holistic approach to research might be preferable.
Exogenous zeitgebergs
External stimuli important in the accurate control of biological rhythm.
Endogenous pacemakers
Internal body ‘clocks’ that regulate biological rhythms.
