U1 AOS 2 - Neuroimaging technology

what is neuroimaging

technique that captures a picture of the brain ; non invasive (can be used without entering brain)

neuroimaging techniques

structural neuroimaging - techniques that produce images or scans (eg MRI, CT scan)

functional neuroimaging - provides view for particular aspect of brain (PET and fMRI)

Computerised Technology (CT) - STRUCTURAL

• x ray equipment that scans the brain at diff angles

• creates horizontal cross section of brain

• needs ‘contrast’ to highlight blood vessels

• limitations : not as detailed as other scanners

Magnetic Resonance Imaging (MRI) - STRUCTURAL

• magnetic fields vibrate atoms in brain to make an image

• produces more clearer,detailed images

• can detect small changes (e.g. cancerous and non cancerous tissues)

positron emission tomography (PET) - FUNCTIONAL

• Produces colour images (shows brains structure, activity,function)

• records level of activity in brain areas during tasks

• less detailed than MRI

  • color code indicates activity levels: violet, blue, green, yellow, and red (highest).

Functional Magnetic Resonance (fMRI) FUNCTIONAL

• Detects + records brain activity by measuring oxygen consumption. (Identifies brain areas by detecing changes in blood ox levels)

• gives better images than PET, gives detailed images in quick time.

Electroencephalography (EEG)

• Detects, amplifies, and records general patterns of electrical activity in the brain.

• used to study states of consciousness (awake, sleeping) + brain disorders (epilepsy, parkinsons)

other functional neuroimaging btechniques

• Magnetoencephalography (MEG).

• Near infra-red spectroscopy (NRIS).

• Diffuse optical tomography (DOT).

Major brain reigions

hindbrain ; medulla, pons, cerebellum

midbrain : reticular formation, substantial nigra

forebrain : hypothalamus, thalamus, cerebrum.

Hindbrain

• basic survival functions

Hindbrain : Medulla

• control vital functions (breathing, heart rate) CONNECTS SPINAL CORD TO BRAIN

Hindbrain : Pons

• involved in sleep, dreaming, coordination

Hindbrain : Cerebellum

• coordinates voluntary movements and balance.

midbrain

• sensory processing and arousal

  Reticular Formation: filters sensory info, consciousness, sleep-wake cycle.

Reticular Formation : Midbrain

• Reticular Formation: filters sensory info, consciousness, sleep-wake cycle.

Forebrain

• involved in thinking and emotions

Hypothalamus - Forebrain

• regulates body functions (hunger, thirst, hormones).

Thalamus - Forebrain

• sensory relay station (except smell), attention, arousal.

Cerebrum - forebrain

• complex thought, emotion, memory, learning.

limbic system

• generally controls emotional behaviour

• interconnected group of forebrain structures : includes amygdala, hippocampus, thalamus, hypothalamus.

cerebral cortex

STRUCTURE

• Outer layer of the cerebrum.

• Divided into left & right hemispheres, connected by the corpus callosum.

FUNCTIONS

• Higher mental functions: thinking, planning, decision-making.

• Divided into sensory, motor, and association areas.

Cortical Lobes

frontal lobe, parietal lobe, occipital lobe, temporal lobe

frontal love

• Planning, decision-making, personality.

• Primary Motor Cortex: voluntary movements.

• Broca’s Area: speech production (left hemisphere).

parietal lobe

• Sensory processing, spatial awareness.

• Primary Somatosensory Cortex: touch sensations.

Occipital Lobe

• Visual processing.

• Primary Visual Cortex: interprets info from eyes.

Temporal lobe

• Memory, hearing, facial recognition.

• Primary Auditory Cortex: processes sound.

• Wernicke’s Area: speech comprehension (left hemisphere)