AVE6320543: United States, 1960s: animation shows chambers of heart filling with blood / Bridgeman Images

AVE6320545: 1950s: Mother talks to baby crying on changing table / Bridgeman Images

AVE6320548: 1950s: Toddler in bathtub washes his face and head with washcloth / Bridgeman Images

AVE6320557: 1950s: Mother bounces baby on her hip, smiling / Bridgeman Images

AVE6320563: United States, 1960s: people play in swimming pool / Bridgeman Images

AVE6320766: 1970s: Model of human brain, lit up / Bridgeman Images

AVE6320772: 1970s: Model of human brain with lights flashes on and off, the basal ganglia remain lit / Bridgeman Images

AVE6320773: 1970s: Flashing lights on abstract object / Bridgeman Images

AVE6320775: 1970s: Model of human brain with lights, flashing / Bridgeman Images

AVE6320781: 1970s: Water / Bridgeman Images

AVE6320786: 1970s: Bucket full of fish lifted from deck of ship onto dock / Bridgeman Images

AVE6320787: 1970s: Fish swimming in tank of water / Bridgeman Images

AVE6320791: 1970s: Hands dissecting squid / Bridgeman Images

AVE6320794: 1970s: Squid at bottom of tank / Bridgeman Images

AVE6320802: 1970s: Man speaks / Bridgeman Images

AVE6320805: 1970s: Infant sleeps on stomach / Bridgeman Images

AVE6320812: 1970s: Infant sleeps in isolette / Bridgeman Images

AVE6320816: 1970s: Man holds up x-ray of skull / Bridgeman Images

AVE6320817: 1970s: Marker points at image / Bridgeman Images

AVE6320824: 1970s: Hands rub baby's back in isolette / Bridgeman Images

AVE6320839: 1960s: Band on stage / Bridgeman Images

AVE6320841: 1960s: Woman and man sing into microphone on stage with band / Bridgeman Images

AVE6320858: 1960s: Women sing into microphone in front of band / Bridgeman Images

AVE6320862: 1960s: Man in suit sits beneath wall design and talks while looking at camera / Bridgeman Images

AVE6320864: 1960s: Man sings while playing guitar / Bridgeman Images

AVE6320870: 1960s: Man plays guitar while sitting / Bridgeman Images

AVE6320881: 1960s: Man playing trombone in a band / Bridgeman Images

AVE6320892: 1960s: Woman plays piano, then starts stalking / Bridgeman Images

AVE6320901: 1960s: Marching band plays music in funeral procession while marching down street in New Orleans / Bridgeman Images

AVE6320903: 1960s: Funeral procession reaches cemetery, casket is raised and inserted into mausoleum / Bridgeman Images

AVE6320913: 1960s: Riverboat goes down Mississippi / Bridgeman Images

AVE6320922: 1960s: Five men wearing hats and formal clothing stand and play a variety of stringed instruments while singing into a microphone / Bridgeman Images

AVE6320942: 1960s: Man wearing cowboy hat and formal clothing speaks into microphone / Bridgeman Images

AVE6320946: Folk group Peter Paul and Mary 1960s / Bridgeman Images

AVE6320949: 1960s: Close up view of woman singing / Bridgeman Images

AVE6320961: 1960s: View of street sign pans to building / Bridgeman Images