Structure and Function Flashcards
Describe the myelencephalon
- Medulla - Regulates vital functions e.g. breathing, circulation
- Contains reticular formation
- Part of the hindbrain - carries tracts with signals between rest of brain and body
Describe the metencephalon
- Hindbrain
- Pons - Governs sleep and arousal
- Cerebellum - Sensorimotor structure, detects errors in movements and makes adjustments
Describe the mesencephalon
Midbrain: Connection point between the forebrain and hindbrain. Main highway for signals transported from cortex to rest of brainstem.
Two divisions
Tectum
- Dorsal surface of midbrain.
- 2 bumps. Posterior and anterior
Tegmentum
- Ventral to tectum
- Substantia nigra and red nucleus. Sensorimotor.
- Dopamine production.
- Damage associated with Parkinson’s.
- Reticular formation
- Cerebral aqueduct
- Periaqueductal gray
Describe the diencephalon
Forebrain - Processes information related to complex cognitive activities, sensory and associative functions and voluntary motor activities.
Thalamus - Relay centre for incoming sensory info. Two lobes joined by the massa intermedia
Hypothalamus - Regulation of motivated behaviours e.g. sleep, thirst. Exerts effects by releasing hormones from pituitary gland.
Describe the telencephalon
Forebrain, largest part
Cerebral cortex - Tissue covering cerebral hemisphere. Gray matter. Central and lateral fissures divided hemisphere into 4 lobes.
Major Gyri: Precentral gyri, poscentral gyri, superior-temporal gyri, cingulate gyri.
Hippocampus - Learning and memory - Neocortex
Describe the limbic system
Regulates motivated behaviours
- Amygdala: Emotional behaviour, aggression and fear
- Cingulate Cortex: Large strip of cortex in the cingulate gyrus
- Fronix: Encircles the dorsal thalamus
- Septum: Midline nucleus located at anterior tip of cingulate cortex
- Hippocampus
Describe the basal ganglia
- Amygdala
- Caudate connected to it is the Putamen. Both together make the striatum.
- Globus pallidus - Voluntary motor responses
- Nucleus accumbens
Single-Unit Recording
Study single neurons using micro-electrode.
Describe the research techniques of experimental cognitive psychology and determine its effectiveness
Controlled lab conditions in which compare one condition with another and then test data statistically.
Limitations
- Lacks ecological validity
- Measures such as response times are indirect
- Need understanding of brain function
- Written theories can be poorly defined
- Indvs diffs
Describe what is cognitive neuropsychology
Study of patterns of cognitive performance by brain damaged individuals to provide knowledge about normal human cognition.
E.g. patient HM Assumes that functional and anatomical modularity.
Limitations
- Damage is extensive
- Diverse patients with broadly similar brain damage
Computed Tomography (CT)
- Visualise the brain through use of x-rays.
- Image is of a horizontal section of the brain
- Combined to create a 3D image.
- Structure
Magnetic Resonance Imaging
MRI
- High resolution images
- Hydrogen atoms activated by radio-frequency waves in magnetic field
- High spatial resolution (detects differences in spatial location)
- 3D images
- Structure
Positron Emission Tomography
PET
- Radioactive liquid injected into body which collects in brain’s blood vessels. Active areas attract liquid producing images of activity
- Poor temporal resolution
- Reasonable spatial resolution
- Allows to identify distribution of molecules in the brain e.g. neurotransmitters.
- Function
Functional MRI
fMRI
- Images of oxygen flow in blood to active areas of brain.
- Oxygenated blood has magnetic properties
- Poor temporal resolution - poor at specifying timing of neural events.
- Images of the BOLD signal.
Advantages
- No injections
- Structural and functional info
- Better spatial resolution
- Produce 3D images
Transcranial Magnetic Stimulation
TMS
- Coil delivers pulse which stops activity in area acting as a temporary lesion.
- Problems with things such as PET and fMRI as can’t prove that the brain activity caused the cognitive activity.
Scalp Electroencephalography
- Measure of electrical activity in the brain.
- EEG - Usually referred to as Event-related Potentials
- EEG records activity at surface of scalp. Present same stimulus numerous times then average effect.
- High temporal resolution but low spatial resolution
MEG
- Monitor brain activity
- Measures changes in magnetic fields on the surface of the scalp that are produced by changes in the underlying patterns of neural activity.
- Only signals near scalp can be detected as are small.
What are the two divisions of the peripheral nervous system?
Division outside the skull and spine.
Somatic Nervous System
Interacts with external environment. Composed of afferent nerves which carry sensory signals to the CNS and efferent nerves which carry motor signals from the CNS to muscles.
Autonomic NS
Regulates the body’s internal environment. Afferent nerves carry signals from the internal organs to the CNS. Efferent nerves carry motor signals from the CNS to internal organs.
Has 2 kinds of efferent nerves - sympathetic - autonomic motor nerves that project from the CNS and spinal cord. Parasympathetic nerves project from brain and part of spinal cord.
Which division of the brain is this?
Hindbrain
Which area of the cortex is this?
Frontal lobe
Motor activity, speech, planning, impulse control
Which area of the cortex is this?
Parietal Lobe
Integrates sensory information by sensing body position and integrating visual information.
Spatial tasks.
Which area of the cortex is this?
Temporal lobe.
Contains the primary auditory cortex involved in processing auditory information. Left temporal lobe contains Wernicke’s area - involved in language comprehension.
Which area of the cortex is this?
Occipital lobe
Contains the primary visual cortex which handles visual information.
Describe the cerebrum
Controls abstract thought and learning.
Central and lateral fissure divide each hemisphere into 4 lobes - frontal, parietal, temporal, occipital.
What are the different classes of neuron?
Multipolar: 2+ processes extending from cell body
Unipolar: 1 process extending
Bipolar: 2 processes extending
Interneurons: Neurons with a short/no axon. Integrate the neural activity within a single brain structure.
