Related by context. Frequent words. (Click for all words.) 47 cortical 43 cerebral cortex 42 frontal lobe 42 brains 41 cortex 40 neural networks 39 cerebellum 38 brain 38 neuronal 38 testes 38 lobes 38 hippocampus 37 synapse 37 cognition 37 prefrontal cortex 35 plasticity 35 amygdala 35 brainstem 35 synaptic 35 neural 35 perceptual 34 astrocytes 34 nerve cells 34 brain scans 34 glucose metabolism 33 reproductive organs 33 neurons 33 synapses 33 imaging fMRI 33 mitochondria 33 muscle 33 fatty tissue 33 skulls 33 muscle tissue 32 neuron 32 cognitive abilities 32 cerebral 32 retinas 32 internal organs 32 anatomy 31 spinal cords 31 cortisol levels 31 neuroscientists 31 mice 31 circadian rhythms 30 ovaries 30 fMRI 30 organs 30 insides 30 eyelids 30 metabolic 30 muscles 30 cochlea 30 nerve fibers 29 insula 29 recesses 29 motor neurons 29 spinal fluid 29 innards 29 hair follicles 29 cognitive 29 circuitry 29 facial expressions 29 whiskers 29 follicles 29 cognitive functions 29 nerve endings 28 facial muscles 28 livers 28 functional magnetic resonance 28 brainpower 28 subconscious 28 cognitive functioning 27 optic nerve 27 ventricles 27 physiological 27 psyches 27 sperm 27 carotid arteries 27 hypothalamus 27 eye sockets 27 cranium 27 comprehension 27 blood vessels 27 spines 27 intuition 26 gills 26 cognitively 26 overactive 26 neurological 26 adolescence 26 serotonin 26 olfactory 25 vocal chords 25 physiologically 25 intellects 25 hormones 25 cognitive function 25 physiology 24 psyche 24 dark